Management of Ophthalmologic Disorders, Including Macular Degeneration

ABSTRACT

A drag may be used in the preparation of a medicament for the treatment or prevention of an ophthalmologic disorder, wherein the drug inhibits, antagonizes, or short-circuits the visual cycle at a step of the visual cycle that occurs outside a disc of a rod photoreceptor cell.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. patent application Ser. No.11/199,594, filed Aug. 8, 2005; which is a continuation-in-part ofInternational Application No. PCT/US2005/004990, filed Feb. 17, 2005,which claims the benefit of U.S. Provisional Patent Application Ser. No.60/545,456, filed Feb. 17, 2004; U.S. Provisional Patent ApplicationSer. No. 60/567,604, filed May 3, 2004; and U.S. Provisional PatentApplication Ser. No. 60/578,324, filed Jun. 9, 2004. All aforementionedapplications are hereby incorporated herein by reference in theirentirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Support for research leading to subject matter disclosed in thisapplication was provided in part by the National Institutes of HealthGrant Nos. RO1-EY-04096 and/or RO1-EY-015425. Accordingly, the UnitedStates Government has certain rights with respect to subject matter ofthis application.

INTRODUCTION

Age related diseases of vision are an ever-increasing health problem inindustrial societies. Age related macular degeneration (AMD) affectsmillions of persons worldwide and is a leading cause of vision loss andblindness in ageing populations. In this disease, daytime vision (conedominated vision) degrades with time because cone photoreceptors, whichare concentrated in the foveal region of the retina, die. The incidenceof this disease increases from less than 10% of the population 50 yearsof age to over 30% at 75 and continues upwards past this age. The onsetof the disease has been correlated with the accumulation of complex andtoxic biochemicals in and around the retinal pigment epithelium (RPE)and lipofuscin in the RPE. The accumulation of these retinotoxicmixtures is one of the most important known risk factors in the etiologyof AMD. The RPE forms part of the retinal-blood barrier and alsosupports the function of photoreceptor cells, including rods and cones.Among other activities, the RPE routinely phagocytoses spent outersegments of rod cells. In at least some forms of macular degeneration,accumulation of lipofuscin in the RPE is due in part to thisphagocytosis. Retinotoxic compounds form in the discs of rodphotoreceptor outer segments. Consequently, the retinotoxic compounds inthe disc are brought into the RPE, where they impair furtherphagocytosis of outer segments and cause apoptosis of the RPE.Photoreceptors cells, including cone cells essential for daytime vision,then die, denuded of RPE support.

One of the retinotoxic compounds formed in the discs of rod outersegments is N-retinylidene-N-retinylethanolamine (A₂E), which is animportant component of the retinotoxic lipofuscins. A₂E is normallyformed in the discs but in such small amounts that it does not impairRPE function upon phagocytosis. However, in certain pathologicalconditions, so much A₂E can accumulate in the disc that the RPE is“poisoned” when the outer segment is phagocytosed.

A₂E is produced from all-trans-retinal, one of the intermediates of therod cell visual cycle. During the normal visual cycle (summarized inFIG. 1), all-trans-retinal is produced inside rod outer-segment discs.The all-trans-retinal can react with phosphatidylethanolamine (PE), acomponent of the disc membrane, to form N-retinylidene-PE. Rim protein(RmP), an ATP-binding cassette transporter located in the membranes ofrod outer-segment discs, then transports all-trans-retinal and/orN-retinylidene-PE out of the disc and into rod outer-segment cytoplasm.The environment there favors hydrolysis of the N-retinylidene-PE. Theall-trans-retinal is reduced to all-trans-retinol in the rod cytoplasm.The all-trans-retinol then crosses the rod outer-segment plasma membraneinto the extracellular space and is taken up by cells of the retinalpigment epithelium (RPE). The all-trans-retinol is converted through aseries of reactions to 11-cis-retinal, which returns to thephotoreceptor and continues in the visual cycle. However, defects in RmPcan derange this process by impeding removal of all-trans-retinal fromthe disc. In a recessive form of macular degeneration called Stargardt'sdisease ( 1/10,000 incidence rate often affecting children; 25,000affected individuals in the U.S.), the gene encoding RmP, abcr, ismutated, and the transporter is nonfunctional. As a result,all-trans-retinal and/or N-retinylidene-PE become trapped in the disc.The N-retinylidene-PE can then react with another molecule ofall-trans-retinal to form N-retinylidene-N-retinylethanolamine (A₂E);this is summarized in FIG. 2. As noted above, some A₂E is formed evenunder normal conditions; however, its production is greatly increasedwhen its precursors accumulate inside the discs due to the defectivetransporter, and can thereby cause macular degeneration.

Other forms of macular degeneration may also result from pathologiesthat result in lipofuscin accumulation. A dominant form of Stargardt'sdisease, known as chromosome 6-linked autosomal dominant maculardystrophy (ADMD, OMIM #600110), is caused by a mutation in the geneencoding elongation of very long chain fatty acids-4, elov14.

There are few, if any, preventative treatments for AMD, and therapeuticinterventions are available for only certain, less common, forms of thedisease.

SUMMARY

This disclosure relates to compositions, systems, and methods formanaging macular degeneration, and, more specifically, for preventingthe accumulation of retinotoxic compounds in and around the retinalpigment epithelium.

In one embodiment, the accumulation of A₂E in rod outer-segment discs isprevented or reduced. It has been found that A₂E production in discs canbe reduced by administering a drug that limits the visual cycle. Thelimitation can be achieved in a number of ways. In one approach, a drugcan effectively short-circuit the portion of the visual cycle thatgenerates the A₂E precursor, all-trans-retinal. In another approach, adrug can inhibit particular steps in the visual cycle necessary forsynthesizing all-trans-retinal. In yet another approach, a drug canprevent binding of intermediate products (retinyl esters) to certainchaperone proteins in the retinal pigment epithelium.

In one embodiment, a method of treating or preventing maculardegeneration in a subject may include administering to the subject adrug that short-circuits the visual cycle at a step of the visual cyclethat occurs outside a disc of a rod photoreceptor cell. In anotherembodiment, a method of treating or preventing macular degeneration in asubject may include administering to the subject a drug that inhibitsand/or interferes with at least one of lecithin retinol acyltransferase, RPE65, 11-cis-retinol dehydrogenase, and isomerohydrolase.

In yet another embodiment, a method of identifying a maculardegeneration drug may include administering a candidate drug to asubject having, or at risk for developing, macular degeneration, andmeasuring accumulation of a retinotoxic compound in the retinal pigmentepithelium of the subject.

A wide variety of drugs are contemplated for use. In some embodiments,inhibitors of the visual cycle include retinoic acid analogs. In otherembodiments, drugs that short circuit the visual cycle include aromaticamines and hydrazines.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 depicts the visual cycle.

FIG. 2 depicts the synthesis of A₂E.

FIG. 3 depicts an intervention for short-circuiting the visual cycle.

FIGS. 4A-B show that TDT (A) and TDH (B) bind to mRPE65 with highaffinities.

FIGS. 5A-B show ERG-b effects of TDT and TDH. FIG. 5A shows acuteeffects of drugs 1 h after 50 mg/kg (i.p). FIG. 5B shows persistenteffects of TDT and TDH 3 days after treatment.

FIGS. 6A-C show that certain isoprenoid mRPE65 antagonists inhibit11-cis-retinal regeneration.

FIGS. 7A-D shows that certain isoprenoid mRPE65 antagonists lower A₂Eaccumulation.

DETAILED DESCRIPTION Overview

The present disclosure provides compositions and methods for managingmacular degeneration by preventing or reducing the accumulation of A₂Ein rod outer-segment discs. A₂E accumulation can be prevented or reducedby decreasing the amount of all-trans-retinal present in discs of rodouter segments. In one approach, a drug may be administered thatinhibits one or more enzymatic steps in the visual cycle, so thatproduction of all-trans-retinal is diminished. In another approach, adrug may be administered that drives the isomerization of 11-cis-retinalto all-trans-retinal in the RPE, thereby decreasing the amount11-cis-retinal that returns to the outer segment discs to bere-isomerized to all-trans-retinal.

Definitions

For convenience, before further description of exemplary embodiments,certain terms employed in the specification, examples, and appendedclaims are collected here. These definitions should be read in light ofthe remainder of the disclosure and as understood by a person of skillin the art.

The articles “a” and “an” are used herein to refer to one or to morethan one (i.e., to at least one) of the grammatical object of thearticle. By way of example, “an element” means one element or more thanone element.

The term “access device” is an art-recognized term and includes anymedical device adapted for gaining or maintaining access to an anatomicarea. Such devices are familiar to artisans in the medical and surgicalfields. An access device may be a needle, a catheter, a cannula, atrocar, a tubing, a shunt, a drain, or an endoscope such as an otoscope,nasopharyngoscope, bronchoscope, or any other endoscope adapted for usein the joint area, or any other medical device suitable for entering orremaining positioned within the preselected anatomic area.

The terms “biocompatible compound” and “biocompatibility” when used inrelation to compounds are art-recognized. For example, biocompatiblecompounds include compounds that are neither themselves toxic to thehost (e.g., an animal or human), nor degrade (if the compound degrades)at a rate that produces monomeric or oligomeric subunits or otherbyproducts at toxic concentrations in the host. In certain embodiments,biodegradation generally involves degradation of the compound in anorganism, e.g., into its monomeric subunits, which may be known to beeffectively non-toxic. Intermediate oligomeric products resulting fromsuch degradation may have different toxicological properties, however,or biodegradation may involve oxidation or other biochemical reactionsthat generate molecules other than monomeric subunits of the compound.Consequently, in certain embodiments, toxicology of a biodegradablecompound intended for in vivo use, such as implantation or injectioninto a patient, may be determined after one or more toxicity analyses.It is not necessary that any subject composition have a purity of 100%to be deemed biocompatible; indeed, it is only necessary that thesubject compositions be biocompatible as set forth above. Hence, asubject composition may comprise compounds comprising 99%, 98%, 97%,96%, 95%, 90%, 85%, 80%, 75% or even less of biocompatible compounds,e.g., including compounds and other materials and excipients describedherein, and still be biocompatible.

To determine whether a compound or other material is biocompatible, itmay be necessary to conduct a toxicity analysis. Such assays are wellknown in the art. One example of such an assay may be performed withlive carcinoma cells, such as GT3TKB tumor cells, in the followingmanner: the sample is degraded in 1M NaOH at 37° C. until completedegradation is observed. The solution is then neutralized with 1M HCl.About 200 μL of various concentrations of the degraded sample productsare placed in 96-well tissue culture plates and seeded with humangastric carcinoma cells (GT3TKB) at 10⁴/well density. The degradedsample products are incubated with the GT3TKB cells for 48 hours. Theresults of the assay may be plotted as % relative growth vs.concentration of degraded sample in the tissue-culture well. Inaddition, compounds and formulations may also be evaluated by well-knownin vivo tests, such as subcutaneous implantations in rats to confirmthat they do not cause significant levels of irritation or inflammationat the subcutaneous implantation sites.

The term “biodegradable” is art-recognized, and includes compounds,compositions and formulations, such as those described herein, that areintended to degrade during use. Biodegradable compounds typically differfrom non-biodegradable compounds in that the former may be degradedduring use. In certain embodiments, such use involves in vivo use, suchas in vivo therapy, and in other certain embodiments, such use involvesin vitro use. In general, degradation attributable to biodegradabilityinvolves the degradation of a biodegradable compound into its componentsubunits, or digestion, e.g., by a biochemical process, of the compoundinto smaller subunits. In certain embodiments, two different types ofbiodegradation may generally be identified. For example, one type ofbiodegradation may involve cleavage of bonds (whether covalent orotherwise) in the compound. In such biodegradation, monomers andoligomers typically result, and even more typically, such biodegradationoccurs by cleavage of a bond connecting one or more of substituents of acompound. In contrast, another type of biodegradation may involvecleavage of a bond (whether covalent or otherwise) internal to sidechain or that connects a side chain to the compound. For example, atherapeutic agent or other chemical moiety attached as a side chain tothe compound may be released by biodegradation. In certain embodiments,one or the other or both generally types of biodegradation may occurduring use of a compound. As used herein, the term “biodegradation”encompasses both general types of biodegradation.

The degradation rate of a biodegradable compound often depends in parton a variety of factors, including the chemical identity of the linkageresponsible for any degradation, the molecular weight, crystallinity,biostability, and degree of cross-linking of such compound, the physicalcharacteristics of the implant, shape and size, and the mode andlocation of administration. For example, the greater the molecularweight, the higher the degree of crystallinity, and/or the greater thebiostability, the biodegradation of any biodegradable compound isusually slower. The term “biodegradable” is intended to cover materialsand processes also termed “bioerodible”.

In certain embodiments, if the biodegradable compound also has atherapeutic agent or other material associated with it, thebiodegradation rate of such compound may be characterized by a releaserate of such materials. In such circumstances, the biodegradation ratemay depend on not only the chemical identity and physicalcharacteristics of the compound, but also on the identity of any suchmaterial incorporated therein.

In certain embodiments, compound formulations bio degrade within aperiod that is acceptable in the desired application. In certainembodiments, such as in vivo therapy, such degradation occurs in aperiod usually less than about five years, one year, six months, threemonths, one month, fifteen days, five days, three days, or even one dayon exposure to a physiological solution with a pH between 6 and 8 havinga temperature of between 25 and 37° C. In other embodiments, thecompound degrades in a period of between about one hour and severalweeks, depending on the desired application.

The terms “comprise,” “comprising,” “include,” “including,” “have,” and“having” are used in the inclusive, open sense, meaning that additionalelements may be included. The terms “such as”, “e.g.”, as used hereinare non-limiting and are for illustrative purposes only. “Including” and“including but not limited to” are used interchangeably.

The term “drug delivery device” is an art-recognized term and refers toany medical device suitable for the application of a drug to a targetedorgan or anatomic region. The term includes those devices that transportor accomplish the instillation of the compositions towards the targetedorgan or anatomic area, even if the device itself is not formulated toinclude the composition. As an example, a needle or a catheter throughwhich the composition is inserted into an anatomic area or into a bloodvessel or other structure related to the anatomic area is understood tobe a drug delivery device. As a further example, a stent or a shunt or acatheter that has the composition included in its substance or coated onits surface is understood to be a drug delivery device.

When used with respect to a therapeutic agent or other material, theterm “sustained release” is art-recognized. For example, a subjectcomposition that releases a substance over time may exhibit sustainedrelease characteristics, in contrast to a bolus type administration inwhich the entire amount of the substance is made biologically availableat one time. For example, in particular embodiments, upon contact withbody fluids including blood, tissue fluid, lymph or the like, thecompound matrices (formulated as provided herein and otherwise as knownto one of skill in the art) may undergo gradual degradation (e.g.,through hydrolysis) with concomitant release of any materialincorporated therein, for a sustained or extended period (as compared tothe release from a bolus). This release may result in prolonged deliveryof therapeutically effective amounts of any incorporated a therapeuticagent. Sustained release will vary in certain embodiments as describedin greater detail below.

The term “delivery agent” is an art-recognized term, and includesmolecules that facilitate the intracellular delivery of a therapeuticagent or other material. Examples of delivery agents include: sterols(e.g., cholesterol) and lipids (e.g., a cationic lipid, virosome orliposome).

The term “or” as used herein should be understood to mean “and/or”,unless the context clearly indicates otherwise.

The phrases “parenteral administration” and “administered parenterally”are art-recognized terms, and include modes of administration other thanenteral and topical administration, such as injections, and include,without limitation, intravenous, intramuscular, intrapleural,intravascular, intrapericardial, intraarterial, intrathecal,intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal,transtracheal, subcutaneous, subcuticular, intra-articular, subcapsular,subarachnoid, intraspinal and intrasternal injection and infusion.

The term “treating” is art-recognized and includes inhibiting a disease,disorder or condition in a subject having been diagnosed with thedisease, disorder, or condition, e.g., impeding its progress; andrelieving the disease, disorder or condition, e.g., causing regressionof the disease, disorder and/or condition. Treating the disease orcondition includes ameliorating at least one symptom of the particulardisease or condition, even if the underlying pathophysiology is notaffected.

The term “preventing” is art-recognized and includes stopping a disease,disorder or condition from occurring in a subject which may bepredisposed to the disease, disorder and/or condition but has not yetbeen diagnosed as having it. Preventing a condition related to a diseaseincludes stopping the condition from occurring after the disease hasbeen diagnosed but before the condition has been diagnosed.

The term “fluid” is art-recognized to refer to a non-solid state ofmatter in which the atoms or molecules are free to move in relation toeach other, as in a gas or liquid. If unconstrained upon application, afluid material may flow to assume the shape of the space available toit, covering for example, the surfaces of an excisional site or the deadspace left under a flap. A fluid material may be inserted or injectedinto a limited portion of a space and then may flow to enter a largerportion of the space or its entirety. Such a material may be termed“flowable.” This term is art-recognized and includes, for example,liquid compositions that are capable of being sprayed into a site;injected with a manually operated syringe fitted with, for example, a23-gauge needle; or delivered through a catheter. Also included in theterm “flowable” are those highly viscous, “gel-like” materials at roomtemperature that may be delivered to the desired site by pouring,squeezing from a tube, or being injected with any one of thecommercially available injection devices that provide injectionpressures sufficient to propel highly viscous materials through adelivery system such as a needle or a catheter. When the compound usedis itself flowable, a composition comprising it need not include abiocompatible solvent to allow its dispersion within a body cavity.Rather, the flowable compound may be delivered into the body cavityusing a delivery system that relies upon the native flowability of thematerial for its application to the desired tissue surfaces. Forexample, if flowable, a composition comprising compounds can be injectedto form, after injection, a temporary biomechanical barrier to coat orencapsulate internal organs or tissues, or it can be used to producecoatings for solid implantable devices. In certain instances, flowablesubject compositions have the ability to assume, over time, the shape ofthe space containing it at body temperature.

Viscosity is understood herein as it is recognized in the art to be theinternal friction of a fluid or the resistance to flow exhibited by afluid material when subjected to deformation. The degree of viscosity ofthe compound may be adjusted by the molecular weight of the compound andother methods for altering the physical characteristics of a specificcompound will be evident to practitioners of ordinary skill with no morethan routine experimentation. The molecular weight of the compound usedmay vary widely, depending on whether a rigid solid state (highermolecular weights) desirable, or whether a fluid state (lower molecularweights) is desired.

The phrase “pharmaceutically acceptable” is art-recognized. In certainembodiments, the term includes compositions, compounds and othermaterials and/or dosage forms which are, within the scope of soundmedical judgment, suitable for use in contact with the tissues of humanbeings and animals without excessive toxicity, irritation, allergicresponse, or other problem or complication, commensurate with areasonable benefit/risk ratio.

The phrase “pharmaceutically acceptable carrier” is art-recognized, andincludes, for example, pharmaceutically acceptable materials,compositions or vehicles, such as a liquid or solid filler, diluent,excipient, solvent or encapsulating material, involved in carrying ortransporting any subject composition from one organ, or portion of thebody, to another organ, or portion of the body. Each carrier must be“acceptable” in the sense of being compatible with the other ingredientsof a subject composition and not injurious to the patient. In certainembodiments, a pharmaceutically acceptable carrier is non-pyrogenic.Some examples of materials which may serve as pharmaceuticallyacceptable carriers include: (1) sugars, such as lactose, glucose andsucrose; (2) starches, such as corn starch and potato starch; (3)cellulose, and its derivatives, such as sodium carboxymethyl cellulose,ethyl cellulose and cellulose acetate; (4) powdered tragacanth; (5)malt; (6) gelatin; (7) talc; (8) excipients, such as cocoa butter andsuppository waxes; (9) oils, such as peanut oil, cottonseed oil,sunflower oil, sesame oil, olive oil, corn oil and soybean oil; (10)glycols, such as propylene glycol; (11) polyols, such as glycerin,sorbitol, mannitol and polyethylene glycol; (12) esters, such as ethyloleate and ethyl laurate; (13) agar; (14) buffering agents, such asmagnesium hydroxide and aluminum hydroxide; (15) alginic acid; (16)pyrogen-free water; (17) isotonic saline; (18) Ringer's solution; (19)ethyl alcohol; (20) phosphate buffer solutions; and (21) other non-toxiccompatible substances employed in pharmaceutical formulations.

The term “pharmaceutically acceptable salts” is art-recognized, andincludes relatively non-toxic, inorganic and organic acid addition saltsof compositions, including without limitation, therapeutic agents,excipients, other materials and the like. Examples of pharmaceuticallyacceptable salts include those derived from mineral acids, such ashydrochloric acid and sulfuric acid, and those derived from organicacids, such as ethanesulfonic acid, benzenesulfonic acid,p-toluenesulfonic acid, and the like. Examples of suitable inorganicbases for the formation of salts include the hydroxides, carbonates, andbicarbonates of ammonia, sodium, lithium, potassium, calcium, magnesium,aluminum, zinc and the like. Salts may also be formed with suitableorganic bases, including those that are non-toxic and strong enough toform such salts. For purposes of illustration, the class of such organicbases may include mono-, di-, and trialkylamines, such as methylamine,dimethylamine, and triethylamine; mono-, di- or trihydroxyalkylaminessuch as mono-, di-, and triethanolamine; amino acids, such as arginineand lysine; guanidine; N-methylglucosamine; N-methylglucamine;L-glutamine; N-methylpiperazine; morpholine; ethylenediamine;N-benzylphenethylamine; (trihydroxymethyl)aminoethane; and the like.See, for example, J. Pharm. Sci., 66:1-19 (1977).

A “patient,” “subject,” or “host” to be treated by the subject methodmay mean either a human or non-human animal, such as primates, mammals,and vertebrates.

The term “prophylactic or therapeutic” treatment is art-recognized andincludes administration to the host of one or more of the subjectcompositions. If it is administered prior to clinical manifestation ofthe unwanted condition (e.g., disease or other unwanted state of thehost animal) then the treatment is prophylactic, i.e., it protects thehost against developing the unwanted condition, whereas if it isadministered after manifestation of the unwanted condition, thetreatment is therapeutic (i.e., it is intended to diminish, ameliorate,or stabilize the existing unwanted condition or side effects thereof).

The terms “therapeutic agent”, “drug”, “medicament” and “bioactivesubstance” are art-recognized and include molecules and other agentsthat are biologically, physiologically, or pharmacologically activesubstances that act locally or systemically in a patient or subject totreat a disease or condition, such as macular degeneration. The termsinclude without limitation pharmaceutically acceptable salts thereof andpro-drugs. Such agents may be acidic, basic, or salts; they may beneutral molecules, polar molecules, or molecular complexes capable ofhydrogen bonding; they may be prodrugs in the form of ethers, esters,amides and the like that are biologically activated when administeredinto a patient or subject.

The phrase “therapeutically effective amount” is an art-recognized term.In certain embodiments, the term refers to an amount of a therapeuticagent that, when incorporated into a compound, produces some desiredeffect at a reasonable benefit/risk ratio applicable to any medicaltreatment. In certain embodiments, the term refers to that amountnecessary or sufficient to eliminate, reduce or maintain (e.g., preventthe spread of) a tumor or other target of a particular therapeuticregimen. The effective amount may vary depending on such factors as thedisease or condition being treated, the particular targeted constructsbeing administered, the size of the subject or the severity of thedisease or condition. One of ordinary skill in the art may empiricallydetermine the effective amount of a particular compound withoutnecessitating undue experimentation. In certain embodiments, atherapeutically effective amount of a therapeutic agent for in vivo usewill likely depend on a number of factors, including: the rate ofrelease of an agent from a compound matrix, which will depend in part onthe chemical and physical characteristics of the compound; the identityof the agent; the mode and method of administration; and any othermaterials incorporated in the compound matrix in addition to the agent.

“Radiosensitizer” is defined as a therapeutic agent that, uponadministration in a therapeutically effective amount, promotes thetreatment of one or more diseases or conditions that are treatable withelectromagnetic radiation. In general, radiosensitizers are intended tobe used in conjunction with electromagnetic radiation as part of aprophylactic or therapeutic treatment. Appropriate radiosensitizers touse in conjunction with treatment with the subject compositions will beknown to those of skill in the art.

“Electromagnetic radiation” as used in this specification includes, butis not limited to, radiation having the wavelength of 10-20 to 10meters. Particular embodiments of electromagnetic radiation employ theelectromagnetic radiation of: gamma-radiation (10⁻²⁰ to 10⁻¹³ m), x-rayradiation (10⁻¹¹ to 10⁻⁹ m), ultraviolet light (10 nm to 400 nm),visible light (400 nm to 700 nm), infrared radiation (700 nm to 1.0 mm),and microwave radiation (1 mm to 30 cm).

“Retinol binding protein” (RBP) is the principal carrier ofall-trans-retinol, which comprises over 90% of serum vitamin A. RBP isfound in serum in association with a cotransport protein calledtransthyretin or prealbumin. Within cells, retinol and its metabolitesare bound to retinol-binding proteins in the cytosol and nucleus (Folliet al. J. Biol. Chem., Vol. 277:41970; Ong, et al. (1994) in TheRetinoids: Biology, Chemistry and Medicine (Sporn, M. B., Roberts, A.B., and Goodman, D. S., eds), pp. 283-318, Raven Press Ltd., New York;and Li et al. (1996) Annu. Rev. Nutr. 16, 205). The eye shows a verymarked preference for acquiring retinol from the retinol-RBP complex(Vogel et al. (2002) Biochemistry. 41(51):15360). The RBP familycontains 7 members: RBP1-7. RBP1 is also referred to as cellular RBP1,HGNC:9919, CRABP-I, CRBP, CRBP1, and RBPC, and its nucleotide and aminoacid sequences are set forth in GenBank Accession Nos. NM_(—)002899 andNP_(—)002890. RBP2 is also referred to as cellular RBP2, HGNC:9920,CRABP-II, CRBP2, CRBPII, and RBPC2, and its nucleotide and amino acidsequences are set forth in GenBank Accession Nos. NM_(—)004164 andNP_(—)004155. RBP3 is also referred to as insterstitial RBP3, IRBP;RBPI; D10S64; D10S65; and D10S66, and its nucleotide and amino acidsequences are set forth in GenBank Accession Nos. NM_(—)002900 andNP_(—)002891. RBP4 is also referred to as plasma RBP4, and itsnucleotide and amino acid sequences are set forth in GenBank AccessionNos. NM_(—)006744 and NP_(—)006735. RBP5 is also referred to as cellularRBP5, CRBP3; CRBPIII; and CRBP-III, and its nucleotide and amino acidsequences are set forth in GenBank Accession Nos. NM_(—)031491 andNP_(—)113679. RBP6 is also referred to as cellular retinoic acid-bindingprotein 2, cellular retinoic acid binding protein 2, CRABP2, HGNC:2339,CRABP-II, and its nucleotide and amino acid sequences are set forth inGenBank Accession Nos. NM_(—)001878 and NP_(—)001869. RBP7 is alsoreferred to as cellular RBP7, HGNC:30316, CRBP4, CRBPIV, and MGC70641,and its nucleotide and amino acid sequences are set forth in GenBankAccession Nos: NM_(—)052960 and NP_(—)443192. The RBP that is believedto import Vitamin A into the eye are the CRBPs. Inhibition of other RBPsmay also be used for treating and/or preventing diseases of the eye.

The phrases “systemic administration,” “administered systemically,”“peripheral administration” and “administered peripherally” areart-recognized, and include the administration of a subject compositionor other material at a site remote from the site affected by the diseasebeing treated. Administration of an agent directly into, onto or in thevicinity of a lesion of the disease being treated, even if the agent issubsequently distributed systemically, may be termed “local” or“topical” or “regional” administration. The term “ED₅₀” isart-recognized. In certain embodiments, ED₅₀ means the dose of a drugwhich produces 50% of its maximum response or effect, or alternatively,the dose which produces a pre-determined response in 50% of testsubjects or preparations. The term “LD₅₀” is art-recognized. In certainembodiments, LD₅₀ means the dose of a drug which is lethal in 50% oftest subjects. The term “therapeutic index” is an art-recognized termwhich refers to the therapeutic index of a drug, defined as LD₅₀/ED₅₀.

The terms “incorporated” and “encapsulated” are art-recognized when usedin reference to a therapeutic agent and a compound, such as acomposition disclosed herein. In certain embodiments, these termsinclude incorporating, formulating or otherwise including such agentinto a composition which allows for sustained release of such agent inthe desired application. The terms may contemplate any manner by which atherapeutic agent or other material is incorporated into a compoundmatrix, including for example: the compound is a polymer, and the agentis attached to a monomer of such polymer (by covalent or other bindinginteraction) and having such monomer be part of the polymerization togive a polymeric formulation, distributed throughout the polymericmatrix, appended to the surface of the polymeric matrix (by covalent orother binding interactions), encapsulated inside the polymeric matrix,etc. The term “co-incorporation” or “co-encapsulation” refers to theincorporation of a therapeutic agent or other material and at least oneother a therapeutic agent or other material in a subject composition.

More specifically, the physical form in which a therapeutic agent orother material is encapsulated in compounds may vary with the particularembodiment. For example, a therapeutic agent or other material may befirst encapsulated in a microsphere and then combined with the compoundin such a way that at least a portion of the microsphere structure ismaintained. Alternatively, a therapeutic agent or other material may besufficiently immiscible in a controlled-release compound that it isdispersed as small droplets, rather than being dissolved, in thecompound. Any form of encapsulation or incorporation is contemplated bythe present disclosure, in so much as the sustained release of anyencapsulated therapeutic agent or other material determines whether theform of encapsulation is sufficiently acceptable for any particular use.

The term “biocompatible plasticizer” is art-recognized, and includesmaterials which are soluble or dispersible in the controlled-releasecompositions described herein, which increase the flexibility of thecompound matrix, and which, in the amounts employed, are biocompatible.Suitable plasticizers are well known in the art and include thosedisclosed in U.S. Pat. Nos. 2,784,127 and 4,444,933. Specificplasticizers include, by way of example, acetyl tri-n-butyl citrate(about 20 weight percent or less), acetyl trihexyl citrate (about 20weight percent or less), butyl benzyl phthalate, dibutyl phthalate,dioctylphthalate, n-butyryl tri-n-hexyl citrate, diethylene glycoldibenzoate (c. 20 weight percent or less) and the like.

“Small molecule” is an art-recognized term. In certain embodiments, thisterm refers to a molecule which has a molecular weight of less thanabout 2000 amu, or less than about 1000 amu, and even less than about500 amu.

The term “alkyl” is art-recognized, and includes saturated aliphaticgroups, including straight-chain alkyl groups, branched-chain alkylgroups, cycloalkyl (alicyclic) groups, alkyl substituted cycloalkylgroups, and cycloalkyl substituted alkyl groups. In certain embodiments,a straight chain or branched chain alkyl has about 30 or fewer carbonatoms in its backbone (e.g., C1-C30 for straight chain, C3-C30 forbranched chain), and alternatively, about 20 or fewer. Likewise,cycloalkyls have from about 3 to about 10 carbon atoms in their ringstructure, and alternatively about 5, 6 or 7 carbons in the ringstructure.

Unless the number of carbons is otherwise specified, “lower alkyl”refers to an alkyl group, as defined above, but having from one to aboutten carbons, alternatively from one to about six carbon atoms in itsbackbone structure. Likewise, “lower alkenyl” and “lower alkynyl” havesimilar chain lengths.

The term “aralkyl” is art-recognized and refers to an alkyl groupsubstituted with an aryl group (e.g., an aromatic or heteroaromaticgroup).

The terms “alkenyl” and “alkynyl” are art-recognized and refer tounsaturated aliphatic groups analogous in length and possiblesubstitution to the alkyls described above, but that contain at leastone double or triple bond respectively.

The term “aryl” is art-recognized and refers to 5-, 6- and 7-memberedsingle-ring aromatic groups that may include from zero to fourheteroatoms, for example, benzene, naphthalene, anthracene, pyrene,pyrrole, furan, thiophene, imidazole, oxazole, thiazole, triazole,pyrazole, pyridine, pyrazine, pyridazine and pyrimidine, and the like.Those aryl groups having heteroatoms in the ring structure may also bereferred to as “aryl heterocycles” or “heteroaromatics.” The aromaticring may be substituted at one or more ring positions with suchsubstituents as described above, for example, halogen, azide, alkyl,aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, alkoxyl, amino, nitro,sulfhydryl, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl,silyl, ether, alkylthio, sulfonyl, sulfonamido, ketone, aldehyde, ester,heterocyclyl, aromatic or heteroaromatic moieties, —CF₃, —CN, or thelike. The term “aryl” also includes polycyclic ring systems having twoor more cyclic rings in which two or more carbons are common to twoadjoining rings (the rings are “fused rings”) wherein at least one ofthe rings is aromatic, e.g., the other cyclic rings may be cycloalkyls,cycloalkenyls, cycloalkynyls, aryls and/or heterocyclyls.

The terms ortho, meta and para are art-recognized and refer to 1,2-,1,3- and 1,4-disubstituted benzenes, respectively. For example, thenames 1,2-dimethylbenzene and ortho-dimethylbenzene are synonymous.

The terms “heterocyclyl”, “heteroaryl”, or “heterocyclic group” areart-recognized and refer to 3- to about 10-membered ring structures,alternatively 3- to about 7-membered rings, whose ring structuresinclude one to four heteroatoms. Heterocycles may also be polycycles.Heterocyclyl groups include, for example, thiophene, thianthrene, furan,pyran, isobenzofuran, chromene, xanthene, phenoxanthene, pyrrole,imidazole, pyrazole, isothiazole, isoxazole, pyridine, pyrazine,pyrimidine, pyridazine, indolizine, isoindole, indole, indazole, purine,quinolizine, isoquinoline, quinoline, phthalazine, naphthyridine,quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline,phenanthridine, acridine, pyrimidine, phenanthroline, phenazine,phenarsazine, phenothiazine, furazan, phenoxazine, pyrrolidine, oxolane,thiolane, oxazole, piperidine, piperazine, morpholine, lactones, lactamssuch as azetidinones and pyrrolidinones, sultams, sultones, and thelike. The heterocyclic ring may be substituted at one or more positionswith such substituents as described above, as for example, halogen,alkyl, aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, amino, nitro,sulfhydryl, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl,silyl, ether, alkylthio, sulfonyl, ketone, aldehyde, ester, aheterocyclyl, an aromatic or heteroaromatic moiety, —CF₃, —CN, or thelike.

The terms “polycyclyl” or “polycyclic group” are art-recognized andrefer to two or more rings (e.g., cycloalkyls, cycloalkenyls,cycloalkynyls, aryls and/or heterocyclyls) in which two or more carbonsare common to two adjoining rings, e.g., the rings are “fused rings”.Rings that are joined through non-adjacent atoms are termed “bridged”rings. Each of the rings of the polycycle may be substituted with suchsubstituents as described above, as for example, halogen, alkyl,aralkyl, alkenyl, alkynyl, cycloalkyl, hydroxyl, amino, nitro,sulfhydryl, imino, amido, phosphonate, phosphinate, carbonyl, carboxyl,silyl, ether, alkylthio, sulfonyl, ketone, aldehyde, ester, aheterocyclyl, an aromatic or heteroaromatic moiety, —CF₃, —CN, or thelike.

The term “carbocycle” is art-recognized and refers to an aromatic ornon-aromatic ring in which each atom of the ring is carbon.

The term “nitro” is art-recognized and refers to —NO₂; the term“halogen” is art-recognized and refers to —F, —Cl, —Br or —I; the term“sulfhydryl” is art-recognized and refers to SH; the term “hydroxyl”means —OH; and the term “sulfonyl” is art-recognized and refers to SO₂—.“Halide” designates the corresponding anion of the halogens, and“pseudohalide” has the definition set forth on page 560 of “AdvancedInorganic Chemistry” by Cotton and Wilkinson.

The terms “amine” and “amino” are art-recognized and refer to bothunsubstituted and substituted amines, e.g., a moiety that may berepresented by the general formulas:

wherein R50, R51 and R52 each independently represent a hydrogen, analkyl, an alkenyl, (CH₂)_(m)—R61, or R50 and R51, taken together withthe N atom to which they are attached complete a heterocycle having from4 to 8 atoms in the ring structure; R61 represents an aryl, acycloalkyl, a cycloalkenyl, a heterocycle or a polycycle; and m is zeroor an integer in the range of 1 to 8. In other embodiments, R50 and R51(and optionally R52) each independently represent a hydrogen, an alkyl,an alkenyl, or —(CH₂)_(m)—R61. Thus, the term “alkylamine” includes anamine group, as defined above, having a substituted or unsubstitutedalkyl attached thereto, i.e., at least one of R50 and R51 is an alkylgroup.

The term “acylamino” is art-recognized and refers to a moiety that maybe represented by the general formula:

wherein R50 is as defined above, and R54 represents a hydrogen, analkyl, an alkenyl or —(CH₂)_(m)—R61, where m and R61 are as definedabove.

The term “amido” is art recognized as an amino-substituted carbonyl andincludes a moiety that may be represented by the general formula:

wherein R50 and R51 are as defined above. Certain embodiments of theamide in the present invention will not include imides which may beunstable.

The term “alkylthio” refers to an alkyl group, as defined above, havinga sulfur radical attached thereto. In certain embodiments, the“alkylthio” moiety is represented by one of S alkyl, —S-alkenyl,—S-alkynyl, and —S—(CH₂)_(m)—R61, wherein m and R61 are defined above.Representative alkylthio groups include methylthio, ethyl thio, and thelike.

The term “carboxyl” is art recognized and includes such moieties as maybe represented by the general formulas:

wherein X50 is a bond or represents an oxygen or a sulfur, and R55 andR56 represents a hydrogen, an alkyl, an alkenyl, —(CH₂)_(m)—R61 or apharmaceutically acceptable salt, R56 represents a hydrogen, an alkyl,an alkenyl or —(CH₂)_(m)—R61, where m and R61 are defined above. WhereX50 is an oxygen and R55 or R56 is not hydrogen, the formula representsan “ester”. Where X50 is an oxygen, and R55 is as defined above, themoiety is referred to herein as a carboxyl group, and particularly whenR55 is a hydrogen, the formula represents a “carboxylic acid”. Where X50is an oxygen, and R56 is hydrogen, the formula represents a “formate”.In general, where the oxygen atom of the above formula is replaced bysulfur, the formula represents a “thiolcarbonyl” group. Where X50 is asulfur and R55 or R56 is not hydrogen, the formula represents a“thiolester.” Where X50 is a sulfur and R55 is hydrogen, the formularepresents a “thiolcarboxylic acid.” Where X50 is a sulfur and R56 ishydrogen, the formula represents a “thiolformate.” On the other hand,where X50 is a bond, and R55 is not hydrogen, the above formularepresents a “ketone” group. Where X50 is a bond, and R55 is hydrogen,the above formula represents an “aldehyde” group.

The term “carbamoyl” refers to —O(C═O)NRR′, where R and R′ areindependently H, aliphatic groups, aryl groups or heteroaryl groups.

The term “oxo” refers to a carbonyl oxygen (═O).

The terms “oxime” and “oxime ether” are art-recognized and refer tomoieties that may be represented by the general formula:

wherein R75 is hydrogen, allyl, cycloalkyl, alkenyl, alkynyl, aryl,aralkyl, or —(CH₂)_(m)—R61. The moiety is an “oxime” when R is H; and itis an “oxime ether” when R is alkyl, cycloalkyl, alkenyl, alkynyl, aryl,aralkyl, or —(CH₂)_(m)—R61.

The terms “alkoxyl” or “alkoxy” are art-recognized and refer to an alkylgroup, as defined above, having an oxygen radical attached thereto.Representative alkoxyl groups include methoxy, ethoxy, propyloxy,tert-butoxy and the like. An “ether” is two hydrocarbons covalentlylinked by an oxygen. Accordingly, the substituent of an alkyl thatrenders that alkyl an ether is or resembles an alkoxyl, such as may berepresented by one of —O-alkyl, —O-alkenyl, O-alkynyl, —O—(CH₂)_(m)—R61,where m and R61 are described above.

The term “sulfonate” is art recognized and refers to a moiety that maybe represented by the general formula:

in which R57 is an electron pair, hydrogen, alkyl, cycloalkyl, or aryl.

The term “sulfate” is art recognized and includes a moiety that may berepresented by the general formula:

in which R57 is as defined above.

The term “sulfonamido” is art recognized and includes a moiety that maybe represented by the general formula:

in which R50 and R56 are as defined above.

The term “sulfamoyl” is art-recognized and refers to a moiety that maybe represented by the general formula:

in which R50 and R51 are as defined above.

The term “sulfonyl” is art-recognized and refers to a moiety that may berepresented by the general formula:

in which R58 is one of the following: hydrogen, alkyl, alkenyl, alkynyl,cycloalkyl, heterocyclyl, aryl or heteroaryl.

The term “sulfoxido” is art-recognized and refers to a moiety that maybe represented by the general formula:

in which R58 is defined above.

The term “phosphoryl” is art-recognized and may in general berepresented by the formula:

wherein Q50 represents S or O, and R59 represents hydrogen, a loweralkyl or an aryl. When used to substitute, e.g., an alkyl, thephosphoryl group of the phosphorylalkyl may be represented by thegeneral formulas:

wherein Q50 and R59, each independently, are defined above, and Q51represents O, S or N. When Q50 is S, the phosphoryl moiety is a“phosphorothioate”.

The term “phosphoramidite” is art-recognized and may be represented inthe general formulas:

wherein Q51, R50, R51 and R59 are as defined above. The term“phosphonamidite” is art-recognized and may be represented in thegeneral formulas:

wherein Q51, R50, R51 and R59 are as defined above, and R60 represents alower alkyl or an aryl.

Analogous substitutions may be made to alkenyl and alkynyl groups toproduce, for example, aminoalkenyls, aminoalkynyls, amidoalkenyls,amidoalkynyls, iminoalkenyls, iminoalkynyls, thioalkenyls, thioalkynyls,carbonyl-substituted alkenyls or alkynyls.

The definition of each expression, e.g. alkyl, m, n, and the like, whenit occurs more than once in any structure, is intended to be independentof its definition elsewhere in the same structure.

The term “selenoalkyl” is art-recognized and refers to an alkyl grouphaving a substituted seleno group attached thereto. Exemplary“selenoethers” which may be substituted on the alkyl are selected fromone of -Se-alkyl, -Se-alkenyl, -Se-alkynyl, and -Se-(CH₂)_(m)—R61, m andR61 being defined above.

The terms triflyl, tosyl, mesyl, and nonaflyl are art-recognized andrefer to trifluoromethanesulfonyl, p-toluenesulfonyl, methanesulfonyl,and nonafluorobutanesulfonyl groups, respectively. The terms triflate,tosylate, mesylate, and nonaflate are art-recognized and refer totrifluoromethanesulfonate ester, p-toluenesulfonate ester,methanesulfonate ester, and nonafluorobutanesulfonate ester functionalgroups and molecules that contain said groups, respectively.

The abbreviations Me, Et, Ph, Tf, Nf, Ts, and Ms represent methyl,ethyl, phenyl, trifluoromethanesulfonyl, nonafluorobutanesulfonyl,p-toluenesulfonyl and methanesulfonyl, respectively. A morecomprehensive list of the abbreviations utilized by organic chemists ofordinary skill in the art appears in the first issue of each volume ofthe Journal of Organic Chemistry; this list is typically presented in atable entitled Standard List of Abbreviations.

Certain compounds contained in compositions of the present invention mayexist in particular geometric or stereoisomeric forms. In addition,polymers of the present invention may also be optically active. Thepresent invention contemplates all such compounds, including cis- andtrans-isomers, R- and S-enantiomers, diastereomers, (D)-isomers,(L)-isomers, the racemic mixtures thereof, and other mixtures thereof,as falling within the scope of the invention. Additional asymmetriccarbon atoms may be present in a substituent such as an alkyl group. Allsuch isomers, as well as mixtures thereof, are intended to be includedin this invention.

If, for instance, a particular enantiomer of compound of the presentinvention is desired, it may be prepared by asymmetric synthesis, or byderivation with a chiral auxiliary, where the resulting diastereomericmixture is separated and the auxiliary group cleaved to provide the puredesired enantiomers. Alternatively, where the molecule contains a basicfunctional group, such as amino, or an acidic functional group, such ascarboxyl, diastereomeric salts are formed with an appropriateoptically-active acid or base, followed by resolution of thediastereomers thus formed by fractional crystallization orchromatographic means well known in the art, and subsequent recovery ofthe pure enantiomers.

It will be understood that “substitution” or “substituted with” includesthe implicit proviso that such substitution is in accordance withpermitted valence of the substituted atom and the substituent, and thatthe substitution results in a stable compound, e.g., which does notspontaneously undergo transformation such as by rearrangement,cyclization, elimination, or other reaction.

The term “substituted” is also contemplated to include all permissiblesubstituents of organic compounds. In a broad aspect, the permissiblesubstituents include acyclic and cyclic, branched and unbranched,carbocyclic and heterocyclic, aromatic and nonaromatic substituents oforganic compounds. Illustrative substituents include, for example, thosedescribed herein above. The permissible substituents may be one or moreand the same or different for appropriate organic compounds. Forpurposes of this invention, the heteroatoms such as nitrogen may havehydrogen substituents and/or any permissible substituents of organiccompounds described herein which satisfy the valences of theheteroatoms. This invention is not intended to be limited in any mannerby the permissible substituents of organic compounds.

3. Compositions

As described above, macular degeneration may be treated or prevented byinterfering with the visual cycle in such a way that diminishes theamount of all-trans-retinal present in the discs of the rodphotoreceptor outer segments. Production of retinotoxic compounds bycone cells is negligible and may be ignored, because rods represent 95%of all photoreceptors.

FIG. 1 depicts the mammalian visual cycle. In the course of the visualcycle, a complex of 11-cis-retinal and opsin, known as rhodopsin, passesthrough a series of biochemical steps initiated by the absorption oflight. Various steps of this cycle in distinct places. As FIG. 1illustrates, the initial steps of light absorption to the dissociationof opsin and the formation of all-trans-retinal occur in the discs ofthe rod photoreceptor cell outer segment. The reduction ofall-trans-retinal to all-trans-retinol takes place in the cytoplasm ofthe rod cell, and the remaining steps to regenerate 11-cis-retinal occurin the retinal pigment epithelium (RPE).

At least two broad approaches are contemplated for preventing theaccumulation of all-trans-retinal in the disc. In one approach, one ormore enzymatic steps or chaperone binding steps in the visual cycle maybe inhibited so that the synthetic pathway to all-trans-retinal isblocked. In another approach, a portion of the visual cycle is“short-circuited,” i.e., an early intermediate in the cycle is shuntedto an intermediate that is two or more steps later in the visual cycle,so that these steps of the cycle are bypassed while theall-trans-retinal precursors are not in the disc.

A. Enzyme Inhibitors

Limiting the flux of retinoids through the visual cycle can be achievedby inhibiting any of the key biochemical reactions of the visual cycle.Each step of the cycle is potentially addressable in this fashion.Inhibiting an enzymatic step could thus be used to “stall” the visualcycle in the RPE, thereby keeping all-tran's-retinal out of the discs.

Other steps in the visual cycle are also prone to inhibition. Forexample, as shown in FIG. 1, several enzymes act upon all-trans-retinoland its derivatives upon its return to the RPE, including LRAT (lecithinretinol acyl transferase), 11-cis-retinol dehydrogenase and IMH(isomerohydrolase). In addition, the chaperone RPE65 binds retinylesters to make those typically hydrophobic compounds available to IMHfor processing to 11-cis-retinol. These enzymes and chaperone may betargeted for inhibition and/or interference.

In certain embodiments, an inhibitor of isomerohydrolase (IMH), aninhibitor 11-cis-retinol dehydrogenase, an inhibitor of lecithin retinolacyl transferase (LRAT), or an antagonist of chaperone retinal pigmentepithelium (RPE65) has a structure represented by formula I:

wherein, independently for each occurrence,

n is 0 to 10 inclusive;

R¹ is hydrogen or alkyl;

R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl,or aralkyl;

Y is —C(R_(b))_(p)—, —C(═O)— or —C(R_(b))_(p)C(═O)—;

X is —O—, —N(R_(a))-, —C(R_(b))_(p)— or —S—;

Z is alkyl, haloalkyl, —(CH₂CH₂O)_(p)R_(b) or —C(═O)R_(b);

p is 0 to 20 inclusive;

R_(a) is hydrogen, alkyl, aryl or aralkyl;

R_(b) is hydrogen, alkyl or haloalkyl; and

denotes a single bond, a cis double bond, or a trans double bond.

In certain embodiments, an inhibitor of isomerohydrolase (IMH), aninhibitor 11-cis-retinol dehydrogenase, an inhibitor of lecithin retinolacyl transferase (LRAT), or an antagonist of chaperone retinal pigmentepithelium (RPE65) has a structure represented by formula II:

-   -   wherein, independently for each occurrence,    -   n is 0 to 10 inclusive;    -   R¹ is hydrogen or alkyl;    -   R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   Y is —C(R_(b))_(p)—, —C(═O)— or —C(R_(b))_(p)C(═O)—;    -   X is hydrogen, —O—, —S—, —N(R_(a))-, —N(R_(a))—N(R_(a))-,        —C(═O)—, —C(═NR_(a))-, —C(═NOH)—, —C(═S)— or —C(R_(b))_(p)-;    -   Z is absent, hydrogen, alkyl, haloalkyl, aryl, aralkyl, —CN,        —OR_(b), —(CH₂CH₂O)_(p)R_(b), —C(═O)R_(b), —C(═O)CH₂F,        —C(═O)CHF₂, —C(═O)CF₃, —C(═O)CHN₂, —C(═O)OR_(b),    -   —C(═O)CH₂C(═O)R_(b), —C(═O)C(═C(R_(b))₂)R_(b),

-   -   p is 0 to 20 inclusive;    -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and        denotes a single bond, a cis double bond or a trans double bond.

In certain embodiments, an inhibitor of isomerohydrolase (IMH), aninhibitor 11-cis-retinol dehydrogenase, an inhibitor of lecithin retinolacyl transferase (LRAT), or an antagonist of chaperone retinal pigmentepithelium (RPE65) has a structure represented by formula III:

-   -   wherein, independently for each occurrence,    -   n is 0 to 10 inclusive;    -   R¹ is hydrogen or alkyl;    -   R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   Y is —CR_(b)(OR_(b))-, —CR_(b)(N(R_(a))₂)—, —C(R_(b))_(p)—,        —C(═O)— or —C(R_(b))_(p)C(═O)—;    -   X is —O—, —S—, —N(R_(a))-, —C(═O)—, or —C(R_(b))_(p)-;    -   Z is hydrogen, alkyl, haloalkyl, aryl, aralkyl, —OR_(b),        —N(R_(b))₂, —(CH₂CH₂O)_(p)R_(b), —C(═O)R_(b), —C(═NR_(a))R_(b),        —C(═NOR_(b))R_(b), —C(OR_(b))(R_(b))₂, —C(N(R_(a))₂)(R_(b))₂ or        —(CH₂CH₂O)_(p)R_(b);    -   p is 0 to 20 inclusive;    -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and        denotes a single bond or a trans double bond.

In certain embodiments, an inhibitor of isomerohydrolase (IMH), aninhibitor 11-cis-retinol dehydrogenase, an inhibitor of lecithin retinolacyl transferase (LRAT), or an antagonist of chaperone retinal pigmentepithelium (RPE65) has a structure represented by formula VI:

wherein, independently for each occurrence,

R¹ is hydrogen, alkyl, aryl or aralkyl;

X is alkyl, alkenyl, —C(R_(b))₂-, —C(═O)—, —C(═NR_(a))-, —C(OH)R_(b) or—C(N(R_(a))₂)R_(b)—;

R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl,or aralkyl;

R_(a) is hydrogen, alkyl, aryl or aralkyl; and

R_(b) is hydrogen or alkyl.

In certain embodiments, an inhibitor of isomerohydrolase (IMH), aninhibitor 11-cis-retinol dehydrogenase, an inhibitor of lecithin retinolacyl transferase (LRAT), or an antagonist of chaperone retinal pigmentepithelium (RPE65) has a structure represented by formula I:

wherein, independently for each occurrence,

n is 0 to 10 inclusive;

R¹ is hydrogen or alkyl;

R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl,or aralkyl;

Y is —C(R_(b))_(p)—, —C(═O)— or —C(R_(b))_(p)C(═O)—;

X is —O—, —N(R_(a))-, —C(R_(b))_(p)— or —S—;

Z is alkyl, haloalkyl, —(CH₂CH₂O)_(p)R_(b) or —C(═O)R_(b);

p is 0 to 20 inclusive;

R_(a) is hydrogen, alkyl, aryl or aralkyl;

R_(b) is hydrogen, alkyl or haloalkyl; and

denotes a single bond, a cis double bond, or a trans double bond.

In certain embodiments, an inhibitor of isomerohydrolase (IMH) has astructure represented by formula Ia, Ib, Ic, or Id:

-   -   wherein, independently for each occurrence,    -   n is 0 to 4 inclusive;    -   R¹ is hydrogen or alkyl;    -   R³ is hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl,        heteroaryl, aralkyl, aralkyenyl, aralkynyl, heteroaralkyl,        heteroaralkyenyl, heteroaralkynyl, cyano, nitro, sulfhydryl,        hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,        carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,        sulfamoyl, sulfonyl, and sulfoxido;    -   R⁴ is absent, hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl,        heteroaryl, aralkyl, aralkyenyl, aralkynyl, heteroaralkyl,        heteroaralkyenyl, heteroaralkynyl, cyano, nitro, sulfhydryl,        hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,        carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,        sulfamoyl, sulfonyl, and sulfoxido;    -   Y is —C(R_(b))₂- or —C(═O)—;    -   X is —O—, —N(R_(a))-, —C(R_(b))₂- or —S—;    -   Z is alkyl, haloalkyl or —C(═O)R_(b);    -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl or haloalkyl; and        denotes a single bond, a cis double bond, or a trans double        bond.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein R¹ is methyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein n is 0.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein n is 1.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein Y is —CH₂—.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein X is —O—.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein X is —N(H)—.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein Z is —C(═O)R_(b).

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein Z is —C(═O)R_(b); andR_(b) is haloalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein Z is alkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein Z is haloalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein R³ is hydrogen.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ia, Ib, Ic, or Id, wherein R⁴ is hydrogen, methylor absent.

In certain embodiments, an inhibitor of isomerohydrolase (IMH) has astructure represented by formula Ie, If, Ig, or Ih:

-   -   wherein, independently for each occurrence,    -   n is 0 to 4 inclusive;    -   R¹ is hydrogen or alkyl;    -   R³ is hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl,        heteroaryl, aralkyl, aralkyenyl, aralkynyl, heteroaralkyl,        heteroaralkyenyl, heteroaralkynyl, cyano, nitro, sulfhydryl,        hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,        carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,        sulfamoyl, sulfonyl, and sulfoxido;    -   X is —O—, —N(R_(a))-, —C(R_(b))₂- or —S—;    -   Z is alkyl, haloalkyl or —C(═O)R_(b);    -   R_(a) is hydrogen, alkyl, aryl or aralkyl; and    -   R_(b) is hydrogen, alkyl or haloalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein n is 0.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein n is 1.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein X is —O—.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein X is —N(H)—.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein Z is —C(═O)R_(b).

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein Z is —C(═O)R_(b); andR_(b) is haloalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein Z is alkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein Z is haloalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein R³ is hydrogen.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein X is —O—; and Z isalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein X is —O—; and Z ishaloalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein X is —N(H)—; and Z isalkyl.

In further embodiments, an inhibitor of isomerohydrolase (IMH) has thestructure of formula Ie, If, Ig, or Ih, wherein X is —N(H)—; and Z ishaloalkyl.

In one embodiment, an inhibitor of isomerohydrolase (IMH) is11-cis-retinyl bromoacetate (cBRA):

In certain embodiments, an inhibitor of isomerohydrolase (IMH), aninhibitor 11-cis-retinol dehydrogenase, an inhibitor of lecithin retinolacyl transferase (LRAT), or an antagonist of chaperone retinal pigmentepithelium (RPE65) has a structure represented by formula II:

-   -   wherein, independently for each occurrence,    -   n is 0 to 10 inclusive;    -   R¹ is hydrogen or alkyl;    -   R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   Y is —C(R_(b))_(p)—, —C(═O)— or —C(R_(b))_(p)C(═O)—;    -   X is hydrogen, —O—, —S—, —N(R_(a))-, N(R_(a))—N(R_(a))-,        —C(═O)—, C(═NR_(a))-, —C(═NOH)—, —C(═S)— or —C(R_(b))_(p)-;    -   Z is absent, hydrogen, alkyl, haloalkyl, aryl, aralkyl, —CN,        —OR_(b), —(CH₂CH₂O)_(p)R_(b), —C(═O)R_(b), —C(═O)CH₂F,        —C(═O)CHF₂, —C(═O)CF₃, —C(═O)CHN₂, —C(═O)OR_(b),        —C(═O)CH₂C(═O)R_(b), —C(═O)C(═C(R_(b))₂)R_(b),

-   -   p is 0 to 20 inclusive;    -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and        denotes a single bond, a cis double bond or a trans double bond.

In certain embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIe,or IId:

-   -   wherein, independently for each occurrence,    -   n is 0 to 4 inclusive;    -   R¹ is hydrogen or alkyl;    -   R³ is hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl,        heteroaryl, aralkyl, aralkyenyl, aralkynyl, heteroaralkyl,        heteroaralkyenyl, heteroaralkynyl, cyano, nitro, sulfhydryl,        hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,        carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,        sulfamoyl, sulfonyl, and sulfoxido;    -   R⁴ is absent, hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl,        heteroaryl, aralkyl, aralkyenyl, aralkynyl, heteroaralkyl,        heteroaralkyenyl, heteroaralkynyl, cyano, nitro, sulfhydryl,        hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,        carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,        sulfamoyl, sulfonyl, and sulfoxido;    -   Y is —C(═O)— or —C(R_(b))₂-;    -   X is hydrogen, —O—, —S—, —N(R_(a))-, —N(R_(a))—N(R_(a))-,        —C(═O)—, —C(═NR_(a))-, —C(═NOH)—, —C(═S)— or —C(R_(b))₂-;    -   Z is absent, hydrogen, alkyl, haloalkyl, aryl, aralkyl, —CN,        —OR_(b), —C(═O)R_(b), —C(═O)CH₂F, —C(═O)CHF₂, —C(═O)CF₃,        —C(═O)CHN₂, —C(═O)CH₂OC(═O)R_(b), —C(═O)OR_(b),        —C(═O)C(═C(R_(b))₂)R_(b),

-   -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and        denotes a single bond, a cis double bond or a trans double bond.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein n is 0.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein n is 1.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein R¹ is hydrogen or methyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein R³ is hydrogen.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein R⁴ is hydrogen or methyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein Y is —CH₂—

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein X is —O—.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein X is —NH—.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein X is —C(R_(b))₂-.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein X is —C(═O)—.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein Z is alkyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIa, IIb, IIc,or IId, wherein Z is haloalkyl.

In certain embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh:

-   -   wherein, independently for each occurrence,    -   n is 0 to 4 inclusive;    -   R¹ is hydrogen or alkyl;    -   R³ is hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl,        heteroaryl, aralkyl, aralkyenyl, aralkynyl, heteroaralkyl,        heteroaralkyenyl, heteroaralkynyl, cyano, nitro, sulfhydryl,        hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,        carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,        sulfamoyl, sulfonyl, and sulfoxido;    -   X is hydrogen, —O—, —S—, —N(R_(a))-, —N(R_(a))—N(R_(a))-,        —C(═O)—, —C(═NR_(a))-, —C(═NOH)—, —C(═S)— or —C(R_(b))₂-;    -   Z is absent, hydrogen, alkyl, haloalkyl, aryl, aralkyl, —CN,        —OR_(b), —C(═O)R_(b), —C(═O)CH₂F, —C(═O)CHF₂, —C(═O)CF₃,        —C(═O)CHN₂, —C(═O)CH₂C(═O)R_(b), —C(═O)OR_(b),        —C(═O)C(═C(R_(b))₂)R_(b),

-   -   R_(a) is hydrogen, alkyl, aryl or aralkyl; and    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein n is 0.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein n is 1.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein R¹ is hydrogen or methyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein R³ is hydrogen.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein R⁴ is hydrogen or methyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein X is —O—.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein X is —NH—.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein X is —CH₂—.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein X is —C(═O)—.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein Z is alkyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein Z is haloalkyl.

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein Z is —C(═O)R_(b).

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein X is —O—; and Z is —C(═O)R_(b)—

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula IIe, IIf, IIg,or IIh, wherein X is —CH₂—; and Z is —C(═O)R_(b).

In further embodiments, an inhibitor of lecithin retinol acyltransferase (LRAT) has a structure represented by formula Ie, IIf, IIg,or IIh, wherein X is —NH—; and Z is —C(═O)R_(b).

In one embodiment, an inhibitor of lecithin retinol acyl transferase(LRAT) is 13-desmethyl-13,14-dihydro-all-trans-retunyl trifluoroacetate(RFA):

In one embodiment, an inhibitor of lecithin retinol acyl transferase(LRAT) is all-trans-retinyl α-bromoacetate.

In certain embodiments, an inhibitor of isomerohydrolase (IMH), aninhibitor 11-cis-retinol dehydrogenase, an inhibitor of lecithin retinolacyl transferase (LRAT), or an antagonist of chaperone retinal pigmentepithelium (RPE65) has a structure represented by formula III:

-   -   wherein, independently for each occurrence,    -   n is 0 to 10 inclusive;    -   R¹ is hydrogen or alkyl;    -   R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   Y is —CR_(b)(OR_(b))-, CR_(b)(N(R_(a))₂)—, —C(R_(b))_(p)—,        —C(═O)— or —C(R_(b))_(p)C(═O)—;    -   X is —O—, —S—, —N(R_(a))-, —C(═O)—, or —C(R_(b))_(p)-;    -   Z is hydrogen, alkyl, haloalkyl, aryl, aralkyl, —OR_(b),        —N(R_(b))₂, —(CH₂CH₂O)_(p)R_(b), —C(═O)R_(b), —C(═NR_(a))R_(b),        —C(═NOR_(b))R_(b), —C(OR_(b))(R_(b))₂, —C(N(R_(a))₂)(R_(b))₂ or        —(CH₂CH₂O)_(p)R_(b);    -   p is 0 to 20 inclusive;    -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and        denotes a single bond or a trans double bond.

In certain embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc or IIId:

-   -   wherein, independently for each occurrence,    -   n is 0 to 4 inclusive;    -   R¹ is hydrogen or alkyl;    -   Y is —C(═O)—, —CR_(b)(OR_(b))-, —CR_(b)(N(R_(a))₂)- or        —C(R_(b))₂-;    -   X is —O—, —S—, —N(R_(a))-, —C(═O)—, or —C(R_(b))₂-;    -   Z is hydrogen, alkyl, haloalkyl, aryl, aralkyl, —OR_(b),        —N(R_(b))₂, —C(═O)R_(b), C(═NR_(a))R_(b), —C(═NOH)R_(b),        —C(OR_(b))(R_(b))₂, C(N(R_(a))₂)(R_(b))₂ or —(CH₂CH₂O)_(p)R_(b);    -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl;    -   p is 0 to 10 inclusive; and        denotes a single bond or a trans double bond.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein n is 0.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein n is 1.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein R¹ is hydrogen or methyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein R³ is hydrogen.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein R⁴ is hydrogen or methyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein X is —O—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein X is —NH—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIc, or IIId,wherein X is —C(R_(b))₂-.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIe, orIIId, wherein X is —C(═O)—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein Z is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIa, IIIb, IIIc, orIIId, wherein Z is haloalkyl.

In certain embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh:

-   -   wherein, independently for each occurrence,    -   n is 0 to 4 inclusive;    -   R¹ is hydrogen or alkyl;    -   X is —O—, —S—, —N(R_(a))-, —C(═O)—, or —C(R_(b))₂-;    -   Z is hydrogen, alkyl, haloalkyl, aryl, aralkyl, —OR_(b),        —N(R_(b))₂, —C(═O)R_(b), —C(═NR_(a))R_(b), —C(═NOH)R_(b),        —C(OR_(b))(R_(b))₂, —C(N(R_(a))₂)(R_(b))₂ or        —(CH₂CH₂O)_(p)R_(b);    -   R_(a) is hydrogen, alkyl, aryl or aralkyl;    -   R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and    -   p is 0 to 10 inclusive.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein n is 0.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein n is 1.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein R¹ is hydrogen or methyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein Y is —C(═O)—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein Y is —CH₂—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein Z is —C(═O)R_(b).

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein Z is —CH(OH)R_(b)—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein Z is CH(NH)R_(b).

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein Z is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IIIe, IIIf, IIIg, orIIIh, wherein Z is haloalkyl.

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is 13-cis-retinoic acid (isoretinoin, ACCUTANE®):

In certain embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV:

wherein, independently for each occurrence,

n is 1, 2, 3 or 4;

Y is —C(R_(b))₂-, —C(═O)— or —OC(═O)—;

X is —O—, —NR_(a)—, —C(R_(b))₂- or —C(═O)—;

Z is —C(═O)R_(b), —OR_(b), —N(R_(b))₂, alkyl or haloalkyl;

R_(a) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and

R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl.

In further embodiments, an inhibitor of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein Y is —CH₂—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein X is —O—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein Z is—C(═O)R_(b); and R_(b) is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein Z is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein Y is —CH₂—; Xis —O—; Z is —C(═O)R_(b); and R_(b) is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein Y is —CH₂—; Xis —O—; and Z is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein Y is —CH₂—; Xis —C(═O)—; and Z is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula IV, wherein Y is —CH₂—; Xis —C(═O)—; Z is —N(R_(b))₂; and R_(b) is alkyl.

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is geranyl palmitate (K_(D)=301 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is farnesyl palmitate (K_(D)=63 nM)

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is geranylgeranyl palmitate (K_(D)=213 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is geranyl palmityl ether (K_(D)=416 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is farnesyl palmityl ether (K_(D)=60 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is geranylgeranyl palmityl ether (K_(D)=195 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (K_(D)=96 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (K_(D)=56 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is farnesyl octyl ketone:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is octyl farnesimide:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is palmityl farnesimide:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (K_(D)=56 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (K_(D)=58±5 nM), called13,17,21-Trimethyl-docosa-12,16,20-trien-11-one or “TDT”:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (K_(D)=96±14 nM), called3,7,11-Trimethyl-dodeca-2,6,10-trienoic acid hexadecylamide or “TDH”:

In certain embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V:

wherein, independently for each occurrence,

n is 1, 2 or 3;

Y is —C(R_(b))₂-, —C(═O)— or —CH(OH)—;

X is —O—, NR_(a), or —C(R_(b))₂-;

Z is —C(═O)R_(b), hydrogen, —(CH₂CH₂O)_(p)R_(b), alkyl or haloalkyl;

R_(a) is hydrogen, alkyl, haloalkyl, aryl or aralkyl;

R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl; and

p is 1 to 10 inclusive.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein Y is —CH₂—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein Y is —C(═O)—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein Y is —CH(OH)—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein X is —O—.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein X is —NR_(a)—

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein X is—C(R_(b))-.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein Z is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein Z is—C(═O)R_(b); and R_(b) is alkyl.

In further embodiments, an antagonist of retinal pigment epithelium(RPE65) has a structure represented by formula V, wherein Z is—(CH₂CH₂O)_(p)R_(b); and R_(b) is alkyl.

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is β-ionoacetyl palmitate (K_(D)=153 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is β-ionoacetyl palmityl ether (K_(D)=156 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is retinyl palmitate (4a; K_(D)=47 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is retinyl hexanoate (4b; K_(D)=235 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is retinyl pentanoate:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is retinyl acetate (4c; K_(D)=1,300 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is palmityl retinyl ether (4d, K_(D)=25 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is hexyl retinyl ether (K_(D)=151 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is methyl retinyl ether (K_(D)=24 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is retinyl [2-(2′-methoxy)ethoxy]ethyl ether (K_(D)=486 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is N-palmityl retinimide (K_(D)=40 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is N,N-dimethyl retinimide (K_(D)=3,577 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is N-tert-butyl retinimide (K_(D)=4,321 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is palmityl retinyl alcohol (K_(D)=170 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is methyl retinyl alcohol:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is palmityl retinyl ketone (K_(D)=64 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is retinyl decyl ketone:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is methyl retinyl ketone (K_(D)=3,786 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (4e):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (4f; K_(D)=64 nM)

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (K_(D)=173 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is the following compound (K_(D)=3,786 nM):

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is:

In one embodiment, an antagonist of retinal pigment epithelium (RPE65)is:

The above-described RPE65 antagonist compounds and general formulas ofcompounds, with their various substituent definitions and furtherembodiments, are also LRAT inhibitors, and are incorporated herein byreference as LRAT inhibitors.

Other antagonists of RPE65 and inhibitors of LRAT include agents thatinhibit palmitoylation. For example, 2-bromopalmitate inhibitspalmitoylation. In some embodiments, a racemic mixture of2-bromopalmitate may be applied to inhibit LRAT and/or antagonize RPE65.In other embodiments, purified (R)-2-bromopalmitic acid may be appliedto inhibit LRAT and/or antagonize RPE65. In yet other embodiments,purified (S)-2-bromopalmitic acid may be applied to inhibit LRAT and/orantagonize RPE65.

In certain embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VI:

wherein, independently for each occurrence,

R¹ is hydrogen, alkyl, aryl or aralkyl;

X is alkyl, alkenyl, —C(R_(b))₂-, —C(═O)—, —C(═NR_(a))-, —C(OH)R_(b) or—C(N(R_(a))₂)R_(b)—;

R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl,or aralkyl;

R_(a) is hydrogen, alkyl, aryl or aralkyl; and

R_(b) is hydrogen or alkyl.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VI, wherein R¹ is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VI, wherein X is —C(R_(b))₂-.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VI, wherein X is —C(═O)—.

In certain embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIa or VIb:

wherein, independently for each occurrence,

R¹ is hydrogen, alkyl, aryl or aralkyl;

R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl,or aralkyl;

R³ is hydrogen or alkyl;

R_(a) is hydrogen, alkyl, aryl or aralkyl;

R_(b) is hydrogen or alkyl; and

denotes a single bond, a cis double bond, or a trans double bond.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIa or VIb, wherein R¹ is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIa or VIb, wherein R² is alkyl.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIa or VIb, wherein R³ is hydrogen ormethyl.

In certain embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIc, VId or VIe:

-   -   wherein, independently for each occurrence,    -   n is 1 to 5 inclusive;    -   m is 0 to 30 inclusive;    -   R¹ is hydrogen, alkyl, aryl or aralkyl;    -   R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   R³ is hydrogen or alkyl;    -   R⁴ is hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl,        heteroaryl, aralkyl, aralkyenyl, aralkynyl, heteroaralkyl,        heteroaralkyenyl, heteroaralkynyl, cyano, nitro, sulfhydryl,        hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,        carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,        sulfamoyl, sulfonyl, and sulfoxido;    -   R_(a) is hydrogen, alkyl, aryl or aralkyl; and

R_(b) is hydrogen or alkyl.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIc, wherein R¹ is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIc, wherein R⁴ is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIe, wherein R¹ is hydrogen; and R⁴is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VId, wherein n is 1, 2 or 3.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VId, wherein R³ is methyl.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VId, wherein R¹ is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VId, wherein n is 1, 2 or 3; R³ ismethyl.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VId, wherein n is 1, 2 or 3; R³ ismethyl; and R¹ is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIe, wherein R¹ is hydrogen.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIe, wherein m is 1 to 10 inclusive.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIe, wherein m is 11 to 20 inclusive.

In further embodiments, an inhibitor of 11-cis-retinol dehydrogenase hasa structure represented by formula VIe, wherein m is 11 to 20 inclusive;and R¹ is hydrogen.

11-cis-retinol dehydrogenase inhibitors having structures represented byformula VIe may be generated according to a diversity library approachas shown in Scheme 1, among other ways:

In one embodiment, an inhibitor of 11-cis-retinol dehydrogenas is13-cis-retinoic acid (isoretinoin, ACCUTANE®):

Also included are pharmaceutically acceptable addition salts andcomplexes of the compounds of the formulas given above. In cases whereinthe compounds may have one or more chiral centers, unless specified, thecompounds contemplated herein may be a single stereoisomer or racemicmixtures of stereoisomers. Further included are prodrugs, analogs, andderivatives thereof.

In some embodiments, two or more enzyme inhibitors and/or RPE65 bindinginhibitors may be combined. In some embodiments, an enzyme inhibitorand/or RPE65 binding inhibitor may be combined with a short-circuitingcompound. Combinations may be selected to inhibit sequential steps inthe visual cycle (that is, two steps that occur one immediately afterthe other).

In certain embodiments, an inhibitor of isomerohydrolase (IMH) may be acompound having a structure represented by general structure 1:

-   -   wherein, independently for each occurrence:    -   R, R₁, R₂, and R₃ are H, alkyl, alkenyl, alkynyl, aryl, aralkyl,        heteroaryl, or heteroaralkyl;    -   W and Y are O, NR, R, or S;    -   X is H, alkyl, haloalkyl, aryl, or halide;    -   m and n are integers from 1 to 6 inclusive; and

p is an integer from 0 to 6 inclusive.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein R₂ and R₃ is H or Me.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein m is 2.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein n is 2.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein W is O.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein W is C.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein Y is O.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein p is 1.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein X is Br.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein R₂ and R₃ is H or Me,and m is 2.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 2, and n is 2.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 2, n is 2, and W is O.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 2, n is 2, W is O, and Y is O.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 2, n is 2, W is O, Y is O, and p is 1.

In a further embodiment, the inhibitor of IMH has the structure offormula 1 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 2, n is 2, W is O, Y is O, p is 1, and X is Br.

In one embodiment, an isomerohydrolase inhibitor is 11-cis-retinylbromoacetate (cRBA):

In certain embodiments, an inhibitor of IMH may be a compound of formula8a:

-   -   wherein, independently for each occurrence:    -   X is O, S, NR′, CH₂, or NHNR′;    -   Z is O or NOH;    -   R₁ is —CH₂F, —CHF₂, —CF₃, —CH₂N₂, —CH₂C(O)OR, —OR′, —C(O)CHR′,        —C(NH)CHR′, or —CH═CHR′;    -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   R′″ is CH₃ or H; and    -   n is 0, 1 or 2;    -   wherein        denotes a single bond, a cis double bond or a trans double bond.

Compounds of formula 8a may be considered irreversible inhibitors of IMHbecause they can covalently bind IMH, permanently disabling it.

In certain embodiments, an inhibitor of IMH may be a compound of formula8a wherein Z is O.

In certain embodiments, an inhibitor of IMH may be a compound of formula8b:

-   -   wherein, independently for each occurrence:    -   Y is C═O, C═S, C═NR′, or CH₂;    -   R₁ is R′, —OR′, or —CN;    -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   R′″ is CH₃ or H; and    -   n is 0, 1, or 2;    -   wherein        denotes a single bond, a cis double bond or a trans double bond.

Compounds of formula 8b may be considered reversible inhibitors of IMHbecause they can noncovalently bind IMH without permanently disablingit.

In certain embodiments, an inhibitor of IMH may be a compound of formula8c:

-   -   wherein, independently for each occurrence:    -   X is O, S, NR′, CH₂, or NHNR′;    -   Z is O or NOH;    -   R₁ is —CH₂F, —CHF₂, —CF₃, —CH₂N₂, —CH₂C(O)OR′, —OR′, —C(O)CHR′,        —C(NH)CHR′, or —CH═CHR′;    -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   R′″ is CH₃ or H; and    -   n is 0, 1 or 2.

Compounds of formula 8c may be considered irreversible inhibitors of IMHbecause they can covalently bind IMH, permanently disabling it.

In certain embodiments, an inhibitor of IMH may be a compound of formula8c wherein Z is O.

In certain embodiments, an inhibitor of IMH may be a compound of formula8d:

-   -   wherein, independently for each occurrence:    -   Y is C═O, C═S, C═NR′, or CH₂;    -   R₁ is R′, —OR′, or —CN;    -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   R′″ is CH₃ or H; and    -   n is 0, 1 or 2.

Compounds of formula 8d may be considered reversible inhibitors of IMHbecause they can noncovalently bind IMH without permanently disablingit.

In certain embodiments, an inhibitor of LRAT may be a compound having astructure represented by general structure 2:

-   -   wherein, independently for each occurrence:    -   R, R₁, R₂, and R₃ are H, alkyl, alkenyl, alkynyl, aryl, aralkyl,        heteroaryl, or heteroaralkyl;    -   W and Y are O, NR, R, or S;    -   X is H, alkyl, haloalkyl, or aryl;    -   m and n are integers from 1 to 6 inclusive; and    -   p is an integer from 0 to 6 inclusive.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein R₂ and R₃ is H or Me.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein m is 3.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein n is 1.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein W is O.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein W is C.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein Y is O.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein p is 0.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein X is OCF₃.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein R₂ and R₃ is H or Me,and m is 3.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 3, and n is 1.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 3, n is 1, and W is O.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 3, n is 1, W is O, and Y is O.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 3, n is 1, W is O, Y is O, and p is 0.

In a further embodiment, the inhibitor of LRAT has the structure offormula 2 and the attendant definitions, wherein R₂ and R₃ is H or Me, mis 3, n is 1, W is O, Y is O, p is 0, and X is OCF₃.

An exemplary inhibitor of LRAT is all-trans-retinyl α-bromoacetate.Another exemplary inhibitor of LRAT is13-desmethyl-13,14-dihydro-all-trans-retinyl trifluoroacetate (RFA):

In certain embodiments, a compound that interferes with RPE65 bindingmay be a compound having a structure represented by general structure 3:

-   -   wherein, independently for each occurrence:    -   R and R₁ are H, alkyl, alkenyl, alkynyl, aryl, aralkyl,        heteroaryl, or heteroaralkyl;    -   R₂ is H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,        heteroaralkyl, or —CO₂R;    -   R₃ is H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,        heteroaralkyl, or —CH₂OR₄;    -   R₄ is H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,        heteroaralkyl, heterocyclyl; and    -   m is an integer from 1 to 6 inclusive.

In a further embodiment, the inhibitor of LRAT has the structure offormula 3 and the attendant definitions, wherein R₂ is H, Me, or —CO₂H.

In a further embodiment, the inhibitor of LRAT has the structure offormula 3 and the attendant definitions, wherein m is 4.

In a further embodiment, the inhibitor of LRAT has the structure offormula 3 and the attendant definitions, wherein R₃ is H.

In a further embodiment, the inhibitor of LRAT has the structure offormula 3 and the attendant definitions, wherein R₂ is H, Me, or —CO₂Hand m is 4.

In a further embodiment, the inhibitor of LRAT has the structure offormula 3 and the attendant definitions, wherein R₂ is H, Me, or —CO₂H,m is 4, and R₃ is H.

In certain embodiments, an inhibitor of LRAT may be a compound offormula 6a:

-   -   wherein, independently for each occurrence:    -   X is O, S, NR′, CH₂, or NHNR′;    -   Z is O or NOH;

R₁ is —CH₂F, —CHF₂, —CF₃, —CH₂N₂, —CH₂C(O)OR, —OR′, —C(O)CHR′,—C(NH)CHR′, or —CH═CHR′;

-   -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   n is 1, 2, or 3;    -   wherein        denotes a single bond, a cis double bond or a trans double bond.

Compounds of formula 6a may be considered irreversible inhibitors ofLRAT because they can covalently bind LRAT, permanently disabling it.

In certain embodiments, an inhibitor of LRAT may be a compound offormula 6a wherein Z is O.

In certain embodiments, an inhibitor of LRAT may be a compound offormula 6b:

-   -   wherein, independently for each occurrence:    -   Y is C═O, C═S, C═NR′, or CH₂;    -   R₁ is R′, —OR′, or —CN;    -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   n is 1, 2, or 3;    -   wherein        denotes a single bond, a cis double bond or a trans double bond.

Compounds of formula 6c may be considered reversible inhibitors of LRATbecause they can noncovalently bind LRAT without permanently disablingit.

In certain embodiments, an inhibitor of LRAT may be a compound offormula 6c:

-   -   wherein independently for each occurrence:    -   X is O, S, NR′, CH₂, or NHNR′;    -   Z is O or NOH;

R₁ is —CH₂F, —CHF₂, —CF₃, —CH₂N₂, —CH₂C(O)OR′, —OR′, —C(O)CHR′,—C(NH)CHR′, or —CH═CHR′;

-   -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   n is 1, 2, or 3.

Compounds of formula 6c may be considered irreversible inhibitors ofLRAT because they can covalently bind LRAT, permanently disabling it.

In certain embodiments, an inhibitor of LRAT may be a compound offormula 6c wherein Z is O.

In certain embodiments, an inhibitor of LRAT may be a compound offormula 6d:

wherein, independently for each occurrence:

Y is C═O, C═S, C═NR′, or CH₂;

R₁ is R′, —OR′, or —CN;

R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, orheteroaralkyl;

n is 1, 2, or 3.

Compounds of formula 6d may be considered reversible inhibitors of LRATbecause they can noncovalently bind LRAT without permanently disablingit.

One exemplary embodiment of a compound that interferes with RPE65binding is 13-cis-retinoic acid (isotretinoin, ACCUTANE®):

13-cis-retinoic acid is converted in vivo to all-trans-retinoic acid,which is a powerful inhibitor of RPE65 function.

In certain embodiments, an antagonist of RPE65 is a compound having astructure represented by general structure 4:

-   -   wherein, independently for each occurrence:

R, R₁, R₂ are H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,heteroaralkyl, alkoxy, aryloxy, amino, halo, hydroxy, or carboxyl;

-   -   R₃ is alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,        heteroaralkyl, or ether;

L is H, OH, NH₂, N(R)₂, alkoxy, aryloxy, halo, hydroxy, carboxyl, or twoL taken together represent O, S, or NR;

-   -   X is C(R)₂, O, S, or NR; and    -   m is an integer from 1 to 6 inclusive.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is CH₂.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is NH.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein two Ls taken togetherrepresent O. In a further embodiment, an RPE65 antagonist has thestructure of formula 4 and the attendant definitions, wherein two Lstaken together represent NOH.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein L is H, OH, or NH₂.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein each L is H.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein m is 4.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein m is 3.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein R₂ is H or methyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein R₃ is alkyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein R₃ is ether.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O and two L takentogether represents O.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O and each L is H.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is NH and two L takentogether represents O.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is CH₂ and two Ltaken together represents O.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is CH₂ and two Ltaken together represents NOH.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O, two L takentogether represent O, R₂ is H or methyl, m is 4, and R₃ is a C15 alkyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O, two L takentogether represent O, R₂ is H or methyl, m is 4, and R₃ is a C5 alkyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O, two L takentogether represent O, R₂ is H or methyl, m is 4, and R₃ is methyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O, each L is H, R₂is H or methyl, m is 4, and R₃ is a C15 alkyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is NH, two L takentogether represents O, R₂ is H or methyl, m is 4, and R₃ is a C15 alkyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is CH₂, two L takentogether represents O, R₂ is H or methyl, m is 4, and R₃ is a C15 alkyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O, each L is H, R₂is H or methyl, m is 4, and R₃ is an ether.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is O, each L is H, R₂is H or methyl, m is 4, and R₃ is —CH₂OCH₂CH₂OCH₂CH₂OC₇H₁₅.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is CH₂, two L takentogether represent NOH, R₂ is H or methyl, m is 4, and R₃ is a C15alkyl.

In a further embodiment, an RPE65 antagonist has the structure offormula 4 and the attendant definitions, wherein X is CH₂, L is H, OH,or NH₂, R₂ is H or methyl, m is 4, and R₃ is a C15 alkyl.

In certain embodiments, an inhibitor of RPE65 may be a compound offormula 7a:

-   -   wherein, independently for each occurrence:    -   X is O, S, NR′, CH₂, or NHNR′;    -   Z is O or NOH;

R₁ is —CH₂F, —CHF₂, —CF₃, —CH₂N₂, —CH₂C(O)OR′, —OR′, —C(O)CHR′,—C(NH)CHR′, or —CH═CHR′;

-   -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   n is 1, 2, or 3;    -   wherein        denotes a single bond, a cis double bond or a trans double bond.

Compounds of formula 7a may be considered irreversible antagonists ofRPE65 because they can covalently bind RPE65, permanently disabling it.

In certain embodiments, an inhibitor of RPE65 may be a compound offormula 7a wherein Z is O.

In certain embodiments, an inhibitor of RPE65 may be a compound offormula 7b:

-   -   wherein, independently for each occurrence:    -   Y is O, S, NR′, CH₂═O, C═S, C═NR′, CHOR′, CHNR′R″, CHSR′, or        CH₂;    -   R₁ is R′, —OR′, —CN or (CH₂CH₂O)_(m)R′;    -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;    -   R″ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   m is 1, 2 or 3; and    -   n is 1, 2, or 3;    -   wherein        denotes a single bond, a cis double bond or a trans double bond.

Compounds of formula 7b may be considered reversible antagonists ofRPE65 because they can noncovalently bind RPE65 without permanentlydisabling it.

In certain embodiments, an inhibitor of RPE65 may be a compound offormula 7e:

-   -   wherein, independently for each occurrence:    -   X is O, S, NR′, CH₂, or NHNR′;    -   Z is O or NOH;

R₁ is —CH₂F, —CHF₂, —CF₃, —CH₂N₂, —CH₂C(O)OR′, —OR′, —C(O)CHR′,—C(NH)CHR′, or —CH═CHR′;

-   -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

-   -   n is 1, 2, or 3.

Compounds of formula 7c may be considered irreversible antagonists ofRPE65 because they can covalently bind RPE65, permanently disabling it.

In certain embodiments, an inhibitor of RPE65 may be a compound offormula 7c wherein Z is O.

In certain embodiments, an inhibitor of RPE65 may be a compound offormula 7d:

-   -   wherein, independently for each occurrence:    -   Y is C═O, C═S, C═NR′, CHOH, CHOR′, NH₂, NHR′, NR′R″, SH, SR′, or        CH₂;    -   R₁ is R′, —OR′, —CN or —(CH₂CH₂O)_(m)R′;    -   R′ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;    -   R″ is H, alkyl, heteroalkyl, aryl, heteroaryl, aralkyl, or        heteroaralkyl;

R is

-   -   m is 1, 2 or 3; and    -   n is 1, 2, or 3.

B. Compositions for Short-Circuiting

Short-circuiting the visual cycle can be achieved by catalyzing thethermodynamically downhill isomerization of 11-cis-retinal toall-trans-retinal in the RPE, before the 11-cis-retinal leaves the RPE.FIG. 3 depicts one contemplated intervention. A very wide variety ofsubstances are envisioned as appropriate for this use. Broadly speaking,appropriate drugs include aniline derivates, i.e., a benzene ring withan amine side chain.

Short circuiting molecules operate by first forming a Schiff base with aretinal. When a Schiff base is formed with 11-cis-retinal, isomerizationoccurs. This is the short circuit.

Short-circuit compounds may also trap retinals so that they are notavailable to form A₂E, its precursors or analogs. Withall-trans-retinal, a relatively stable Schiff base can be formed withthe drugs which traps the all-trans-retinal and prevents it from formingA₂E and like compounds. The short-circuit drug competes withphosphatidylethanolamine for binding all-trans-retinal. The trappedcompounds may then be broken down in lysozomes to non-toxic metabolites.A short-circuit drug may disrupt the visual cycle in one or both ways,i.e., by short-circuiting 11-cis-retinals and/or by trappingall-trans-retinals. (A₂E is the best characterized of the lipofuscins.There may be other adducts between all-trans-retinal and amines—or evenproteins—whose formation is initiated by Schiff base formation between areactive retinal and an amine.)

While it is not expected that an aromatic amine/all-trans-retinal Schiffbase will go on to form A₂E-like molecules (because it will be degradedfirst), this can be more reliably prevented by using a short-circuitingdrug that is a secondary amine. This is because the mechanism of A₂Eformation requires a primary amine (two free Hs) because two new N-alkylbonds are made (one with each all-trans-retinal molecule) and thiscannot happen starting with a secondary or tertiary amine. If theshort-circuit drug is a secondary amine, then it can bind only onemolecule of all-trans-retinal and has no remaining site to bind a secondall-trans-retinal, thereby preventing the formation of compoundsanalogous to A₂E akin to the process shown in FIG. 2.

Short-circuit drugs may also provide a long-term effect, so that theiradministration can be infrequent. In some cases, administration may berequired monthly. In other cases, administration may be required weekly.The short-circuit drugs effectively deplete vitamin A stores locally inthe eye by trapping all-trans-retinal. Once the store of vitamin isdiminished by the drug, the visual cycle is impaired, and lipofuscinformation is retarded, which is the goal of therapy. Vitamin A storesare replenished only very slowly in the eye, so that a singleadministration of short-circuit drug may have a prolonged effect. Inaddition, the short-circuit drugs may be cleared slowly from the eye, sothat they may be available for binding over extended periods.

In certain embodiments, a short-circuiting compound has the structurerepresented by formula VII:

-   -   wherein, independently for each occurrence:    -   R is H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,        heteroaralkyl, or carbonyl;    -   L is a hydrophobic moiety, or any two adjacent L taken together        form a fused aromatic or heteroaromatic ring (e.g. a        naphthalene, an anthracene, an indole, a quinoline, etc.).

In certain embodiments, independently for each occurrence, L is alkyl,alkenyl, alkynyl, aryl, aralkyl, heteroaryl, heteroaralkyl, carbonyl,ether, or polycyclic. In certain embodiments, L has the formula VIa:

-   -   wherein, independently for each occurrence:    -   R′ and X are hydrogen, alkyl, alkenyl, alkynyl, aryl, aralkyl,        heteroaryl, heteroaralkyl, carbonyl, alkoxy, hydroxy, thiol,        thioalkyl, or amino; and    -   m is an integer from 1 to 6 inclusive.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula VIb:

wherein n is an integer from 1 to 8 inclusive.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula VIc:

wherein, independently for each occurrence,

R is H, alkyl, or acyl; and

R′ is alkyl or ether.

In a further embodiment, a short circuit drug has the structure offormula VIIc and the attendant definitions, wherein R is H for bothoccurrences.

In a further embodiment, a short circuit drug has the structure offormula VIIc and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula VIIc and the attendant definitions, wherein at least one R ismethyl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula VIId:

wherein, independently for each occurrence:

R is H, alkyl, or acyl; and

R′ is alkyl or ether.

In a further embodiment, a short circuit drug has the structure offormula VIId and the attendant definitions, wherein R is H for bothoccurrences.

In a further embodiment, a short circuit drug has the structure offormula VIId and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula VIId and the attendant definitions, wherein at least one R ismethyl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula VIIe:

wherein, independently for each occurrence:

X is hydrogen or —C(═O)OR′;

R is H, alkyl, or acyl; and

R′ is alkyl.

In a further embodiment, a short circuit drug has the structure offormula VIIe and the attendant definitions, wherein R is H.

In a further embodiment, a short circuit drug has the structure offormula VIIe and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula VIIe and the attendant definitions, wherein R is methyl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula VIIf:

wherein, independently for each occurrence

R is H, alkyl, or acyl; and

R′ is alkyl.

In a further embodiment, a short circuit drug has the structure offormula VIIf and the attendant definitions, wherein R is H.

In a further embodiment, a short circuit drug has the structure offormula VIIf and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula VIIf and the attendant definitions, wherein R is methyl.

In one embodiment, a short circuiting drug is diaminophenoxypentane:

In one embodiment, a short circuiting drug is phenetidine:

In one embodiment, a short circuiting drug is and tricaine:

In one embodiment, a short circuiting drug is 4-butylanaline:

In one embodiment, a short circuiting drug is N-methyl-4-butylanaline:

In one embodiment, a short circuiting drug is ethyl 3-aminobenzoate:

In one embodiment, a short circuiting drug is ethylN-methyl-3-aminobenzoate:

In one embodiment, a short circuiting drug is ethyl 2-aminobenzoate:

In one embodiment, a short circuiting drug is ethylN-methyl-2-aminobenzoate:

In some embodiments, a short circuit drug may be represented by thefollowing generic formula VIII:

-   -   wherein R¹ is hydrogen, alkyl or ether; or any two adjacent L        taken together form a fused aromatic or heteroaromatic ring        (e.g. a naphthalene, an anthracene, etc.).

In certain embodiments, a short-circuiting compound has the structurerepresented by formula IX:

ANR₂  IX

-   -   wherein, independently for each occurrence:    -   R is H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,        heteroaralkyl, or carbonyl; and    -   A is optionally substituted aryl or heteroaryl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula X:

AC(═O)NHNH₂  X

wherein independently for each occurrence:

R′ is hydrogen, alkyl or ether; and

A is optionally substituted aryl or heteroaryl.

In certain embodiments, a short-circuiting compound may have a structurerepresented by general structure 5:

-   -   wherein, independently for each occurrence:    -   R is H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,        heteroaralkyl, or carbonyl;

L is a hydrophobic moiety, or any two adjacent L taken together form afused aromatic ring; and

-   -   n is an integer from 0 to 5 inclusive.

In certain embodiments, independently for each occurrence, L is alkyl,alkenyl, alkynyl, aryl, aralkyl, heteroaryl, heteroaralkyl, carbonyl,ether, or polycyclic. In certain embodiments, L has the formula 5a:

-   -   wherein, independently for each occurrence:

R′ and X are H, alkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl,heteroaralkyl, carbonyl, alkoxy, hydroxy, thiol, thioalkyl, or amino;

-   -   m is an integer from 1 to 6 inclusive; and    -   p is an integer from 0 to 5 inclusive.

Selected specific examples of short circuit drugs includediaminophenoxypentane:

In some embodiments, a short circuit drug may be represented by thefollowing generic formula 5b:

-   -   wherein n is an integer from 1 to 8 inclusive.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula 5c:

-   -   wherein, independently for each occurrence:    -   R is H, alkyl, or acyl; and    -   R′ is alkyl or ether.

In a further embodiment, a short circuit drug has the structure offormula 5c and the attendant definitions, wherein R is H for bothoccurrences.

In a further embodiment, a short circuit drug has the structure offormula 5c and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula 5c and the attendant definitions, wherein at least one R ismethyl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula 5c1:

-   -   wherein, independently for each occurrence:    -   R is H, alkyl, or acyl; and    -   R′ is alkyl or ether.

In a further embodiment, a short circuit drug has the structure offormula 5 μl and the attendant definitions, wherein R is H for bothoccurrences.

In a further embodiment, a short circuit drug has the structure offormula 5 μl and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula 5 μl and the attendant definitions, wherein at least one R ismethyl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula 5d:

-   -   wherein, independently for each occurrence:    -   R is H, alkyl, or acyl; and    -   R′ is alkyl.

In a further embodiment, a short circuit drug has the structure offormula 5d1 and the attendant definitions, wherein R is H.

In a further embodiment, a short circuit drug has the structure offormula 5d and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula 5d and the attendant definitions, wherein R is methyl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula 5d1:

-   -   wherein, independently for each occurrence:    -   R is H, alkyl, or acyl; and    -   R′ is alkyl.

In a further embodiment, a short circuit drug has the structure offormula 5d1 and the attendant definitions, wherein R is H.

In a further embodiment, a short circuit drug has the structure offormula 5d1 and the attendant definitions, wherein at least one R isalkyl.

In a further embodiment, a short circuit drug has the structure offormula 5d1 and the attendant definitions, wherein R is methyl.

In some embodiments, a short circuit drug may be represented by thefollowing generic formula 5e:

-   -   wherein R′ is alkyl or ether.

Diseases associated with lipofuscin accumulation may also be treated orprevented with agents or drugs that prevent vitamin A import into theeye. Exemplary agents are those that prevent vitamin A delivery byretinol binding protein (RBP). Agents may thus be RBP inhibitors orblocking agents. RBP may be a CRBP protein (Ong et al. (1994) Nutr. Rev.52:524 and Cowan et al. (1993) J. Mol. Biol. 230:1225) or a serum RBP(Blomhoff et al. (1990) Science 250:399 and Newcomer et al. (1984) EMBOJ. 3, 1451). A preferred RBP to inhibit is CRBP-1. In an illustrativeembodiment, the RBP blocking agent is fenretinide, a non-retinoidfenretinide analog or a non-retinoid fenretinide isoprenoid. Exemplarycompounds have the structure depicted in formula XI:

-   -   wherein, independently for each occurrence,    -   n is 0 to 10 inclusive;    -   R¹ is hydrogen or alkyl;    -   R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   Z is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, aralkyl, —C(═O)R_(b), or —(CH₂)_(p)R_(b);    -   p is 0 to 20 inclusive;    -   R_(a) is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   R_(b) is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl; and    -   denotes a single bond or a trans double bond.

In a further embodiment a RBP blocking agent has the structure of XI,wherein R¹ is hydrogen or methyl.

In a further embodiment a RBP blocking agent has the structure of XI,wherein Z is aryl.

In a further embodiment a RBP blocking agent has the structure of XI,wherein R_(a) is hydrogen.

In a further embodiment a RBP blocking agent has the structure of XI,wherein R¹ is hydrogen or methyl; Z is aryl; and R_(a) is hydrogen.

In a another embodiment a RBP blocking agent of the invention has thestructure of formula XIa:

-   -   wherein, independently for each occurrence,    -   n is 0 to 10 inclusive;    -   R¹ is hydrogen or alkyl;    -   R² is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl;    -   R³, R⁴, R⁵, R⁶ and R⁷ are hydrogen, halogen, alkyl, alkenyl,        alkynyl, aryl, heteroaryl, aralkyl, aralkyenyl, aralkynyl,        heteroaralkyl, heteroaralkyenyl, heteroaralkynyl, cyano, nitro,        sulfhydryl, hydroxyl, sulfonyl, amino, acylamino, amido,        alkylthio, carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate,        sulfonamido, sulfamoyl, sulfonyl, or sulfoxido;    -   R_(a) is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl; and    -   denotes a single bond or a trans double bond.

In a further embodiment a RBP blocking agent has the structure of XIa,wherein R¹ is hydrogen or methyl.

In a further embodiment a RBP blocking agent has the structure of XIa,wherein R_(a) is hydrogen.

In a further embodiment a RBP blocking agent has the structure of XIa,wherein R¹ is hydrogen or methyl; and R_(a) is hydrogen.

In a further embodiment a RBP blocking agent has the structure of XIa,wherein R³, R⁴, R⁶ and R⁷ are hydrogen.

In a further embodiment a RBP blocking agent has the structure of XIa,wherein R⁵ is hydroxyl.

In a further embodiment a RBP blocking agent has the structure of XIa,wherein R³, R⁴, R⁶ and R⁷ are hydrogen; and R⁵ is hydroxyl.

In a further embodiment a RBP blocking agent has the structure of XIa,wherein R¹ is hydrogen or methyl; R_(a) is hydrogen; R³, R⁴, R⁶ and R⁷are hydrogen; and R⁵ is hydroxyl.

In a another embodiment a RBP blocking agent of the invention has thestructure of formula XIb:

-   -   wherein, independently for each occurrence,    -   n is 0 to 5 inclusive;    -   R¹ is hydrogen or methyl;    -   R² is hydrogen, alkyl, alkenyl, alkynyl, aryl,

-   -   R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are hydrogen, halogen, alkyl, alkenyl,        alkynyl, aryl, heteroaryl, aralkyl, aralkyenyl, aralkynyl,        heteroaralkyl, heteroaralkyenyl, heteroaralkynyl, cyano, nitro,        sulfhydryl, hydroxyl, sulfonyl, amino, acylamino, amido,        alkylthio, carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate,        sulfonamido, sulfamoyl, sulfonyl, or sulfoxido;    -   any two geminal R⁸ and the carbon to which they are bound may        represent C(═O); and    -   R_(a) is hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,        alkynyl, aryl, or aralkyl.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R¹ is hydrogen or methyl.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R_(a) is hydrogen.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R¹ is hydrogen or methyl; and R_(a) is hydrogen.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R³, R⁴, R⁶ and R⁷ are hydrogen.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R⁵ is hydroxyl.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R³, R⁴, R⁶ and R⁷ are hydrogen; and R⁵ is hydroxyl.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R¹ is hydrogen or methyl; R_(a) is hydrogen; R³, R⁴, R⁶ and R⁷are hydrogen; and R⁵ is hydroxyl.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein n is 1 to 3 inclusive.

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R² is

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R² is

In a further embodiment a RBP blocking agent has the structure of XIb,wherein R² is

An RBP inhibitory compound may be a non-retinoid fenretinide analog,such as those set forth above, wherein the analog is not fenretinide.

Vitamin A delivery to the eye may also be inhibited by interfering withthe membrane receptor for holo-RBP, which have been reported to bepresent in the RBP (Vogel et al. (1999) cited in Quadro et al. (1999)EMBO J. 18:4633). Alternatively, the interaction between RBP and itsreceptor may be inhibited.

In yet other embodiments, inhibitors of retinyl-ester isomerase (e.g.,11-cis-retinyl bromoacetate) and/or inhibitors of cellular retinaldehydebinding protein (CRALBP) (e.g., cis-isoprenoids) and/or inhibitors of11-cis-retinol dehydrogenase (e.g., pyrazoles) may be used.

Also included are pharmaceutically acceptable addition salts andcomplexes of the compounds of the formulas given above. In cases whereinthe compounds may have one or more chiral centers, unless specified, thecompounds contemplated herein may be a single stereoisomer or racemicmixtures of stereoisomers. Further included are prodrugs, analogs, andderivatives thereof.

In some embodiments, a combination of one or more compounds describedherein is administered to a subject. Two or more short-circuitingcompounds may be combined. In some embodiments, an enzyme inhibitorand/or RPE65 binding inhibitor may be combined with a short-circuitingcompound. An enzyme inhibitor and/or short-circuiting compound may alsobe combined with one or more agents that prevent the delivery of vitaminA to the eye, such as fenretinide, a non-retinoid fenretinide analog anda non-retinoid isoprenoid. For example, a compound of formula XI may beadministered to a subject who is also receiving a compound of formula I,II, III, IV, V, VI, VII, VIII, IX, or X. Any other combination ofcompounds affecting different target proteins may also be used.

A compound described herein, e.g., a compound of formula XI, may beadministered to a subject who is also receiving a compound selected fromthe group consisting of C-glycoside and arylamide analogues ofN-(4-hydroxyphenyl)retinamide-O-glucuronide, including but not limitedto 4-(retinamido)phenyl-C-glucuronide, 4-(retinamido)phenyl-C-glucoside,4-(retinamido)phenyl-C-xyloside, 4-(retinamido)benzyl-C-glucuronide,4-(retinamido)benzyl-C-glucoside, 4-(retinamido)benzyl-C-xyloside; andretinoyl β-glucuronide analogues such as, for example,1-(β-D-glucopyranosyl) retinamide and1-(D-glucopyranosyluronosyl)retinamide, described in U.S. Pat. Nos.5,516,792, 5,663,377, 5,599,953, 5,574,177, and Bhatnagar et al,Biochem. Pharmacol., 41:1471-7 (1991), each incorporated herein byreference. Other fenretinide derivatives, such as those described inWO2006/063128 and WO2006/007314, may be contemplated for use in certainembodiments. Additional compounds which may be used in combination withthe inventive compounds, e.g., a compound of formula XI, are alsodisclosed in WO2006/063128 and WO2006/007314. Both WO2006/063128 andWO2006/007314 are incorporated herein by reference in their entirety.

In certain embodiments, a compound described herein, e.g., a compound offormula XI, may be administered to a subject who is also receiving avitamin A derivative, including those disclosed in U.S. Pat. No.4,743,400, incorporated herein by reference. These retinoids include,for example, all-trans retinoyl chloride, all-trans-4-(methoxyphenyl)retinamide (methoxyphenyl retinamide), 13-cis-4-(hydroxyphenyl)retinamide and all-trans-4-(ethoxyphenyl) retinamide. U.S. Pat. No.4,310,546, incorporated herein by reference, describesN-(4-acyloxyphenyl)-all-trans retinamides, such as, for example,N-(4-acetoxyphenyl)-all-trans-retinamide,N-(4-propionyloxyphenyl)-all-trans-retinamide andN-(4-N-butyryloxyphenyl)-all-trans-retinamide, all of which arecontemplated for use in certain embodiments. Other vitamin A derivativesor metabolites, such as N-(1H-tetrazol-5-yl)retinamide,N-ethylretinamide, 13-cis-N-ethylretinamide, N-butylretinamide, etretin(acitretin), etretinate, tretinoin (all-trans-retinoic acid) orisotretinoin (13-cis-retinoic acid) may be contemplated for use incertain embodiments. See U.S. Provisional Patent Applications Nos.60/582,293 and 60/602,675; see also Turton et al., Int. J. Exp. Pathol.,73:551-63 (1992), all herein incorporated by reference.

In combination therapies, the compounds may be administeredsimultaneously, e.g., in the form of one composition, or consecutively.When consecutively administered, the time between the twoadministrations may be one or more minutes, one or more hours, one ormore days, or one or more weeks.

Therapeutic or prophylactic treatments with one or more of the compoundsdescribed herein may be combined with other treatments known in the art.For example, they may be used in conjunction with surgery and/orsupplements, and/or radiation, and/or other therapeutic methods.Treatment of the wet form of AMD may be combined a treatment thatremoves or destroys the new blood vessels that grow in or around themacula. A laser, such as a thermal laser may be used for that purpose.Transpupillary thermotherapy is an alternative treatment, in which aninfrared laser is used. Another method is photodynamic therapy, in whicha substance that sensitizes the blood vessels in the eye to laser lightis given intravenously, and then a beam of laser light is used todestroy the abnormal blood vessels. Photocoagulation therapy may also beused.

Treatments may also be combined with administration of an anti-oxidant,e.g., high doses of antioxidants, such as (vitamin C, vitamin E, andbeta-carotene), zinc and copper (“supplementation therapy”). Theantioxidant formulation may contain a combination of vitamin C, vitaminE, and beta-carotene. The specific daily amounts of antioxidants andzinc may be about 500 milligrams of vitamin C; 400 international unitsof vitamin E; 15 milligrams of beta-carotene; 80 milligrams of zinc aszinc oxide; and two milligrams of copper as cupric oxide (used in theAge-Related Eye Disease (ARED) study). A number of new drugs havepromise for the prevention or delay of photoreceptor cell death andretinal degeneration. These drugs include PKC 412 (which blockschemicals in the body that foster new blood vessel growth, orangiogenesis), Glial Derived Neurotrophic Factor (a survival factorwhich has slowed degeneration in a rodent model), and diatazem (acalcium-channel blocker which addresses a rare retinal gene defectcalled beta PDE).

Where a treatment of macular degeneration described herein is combinedwith radiotherapy, preferred forms of radiation for use in the treatmentinclude: proton beam, strontium-90, palladium-103, radiosurgery, andEBRT (external beam radiation therapy). Radiation therapy for “wet”macular degeneration is used to destroy blood vessels and preventneovascularization. Radiation therapy is useful after surgery to preventor reduce scarring by killing or effecting the cells which make up newlyformed blood vessels, inflammatory cells which promote scarring andcells which help create fibrous tissues.

The two therapies may be provided simultaneously or consecutively. Forexample, a surgical method may be applied first, followed byadministration of one or more compounds described herein. Alternatively,a surgical method may be used after administration of one or morecompounds described herein. The second therapeutic method, such assurgery, may also be preceded by and followed by administration of oneor more compounds described herein.

The other therapy may precede or follow the therapeutic agent-basedtherapy by intervals ranging from minutes to days to weeks. Inembodiments where the other macular or retinal degeneration therapy andthe therapeutic agent-based therapy are administered together, one mayprefer to avoid that a significant period of time did not expire betweenthe time of each delivery. In such instances, it is contemplated thatone would administer to a patient both modalities within about 12-24hours of each other and, more preferably, within about 6-12 hours ofeach other, with a delay time of only about 12 hours being mostpreferred. In some situations, it may be desirable to extend the timeperiod for treatment significantly, however, where several days (2, 3,4, 5, 6 or 7) to several weeks (1, 2, 3, 4, 5, 6, 7 or 8) lapse betweenthe respective administrations.

It also is conceivable that more than one administration of either theother macular or retinal degeneration therapy and the therapeuticagent-based therapy will be required to prevent blindness or a decreasein vision. Various combinations may be employed, where the other macularor retinal degeneration therapy is “A” and the therapeutic agent-basedtherapy treatment is “B”, as exemplified below:

A/B/A B/A/B B/B/A A/A/B B/A/A A/B/B B/B/B/A B/B/A/B A/A/B/B A/B/A/BA/B/B/A B/B/A/A B/A/B/A B/A/A/B B/B/B/A A/A/A/B B/A/A/A A/B/A/A A/A/B/AA/B/B/B B/A/B/B B/B/A/B.

Pharmaceutical compositions for use in accordance with the presentmethods may be formulated in conventional manner using one or morephysiologically acceptable carriers or excipients. Thus, activatingcompounds and their physiologically acceptable salts and solvates may beformulated for administration by, for example, injection, inhalation orinsufflation (either through the mouth or the nose) or oral, buccal,parenteral or rectal administration. In one embodiment, the compound isadministered locally, at the site where the target cells, e.g., diseasedcells, are present, i.e., in the eye or the retina.

Compounds can be formulated for a variety of loads of administration,including systemic and topical or localized administration. Techniquesand formulations generally may be found in Remington's PharmaceuticalSciences, Meade Publishing Co., Easton, Pa. For systemic administration,injection is preferred, including intramuscular, intravenous,intraperitoneal, and subcutaneous. For injection, the compounds can beformulated in liquid solutions, preferably in physiologically compatiblebuffers such as Hank's solution or Ringer's solution. In addition, thecompounds may be formulated in solid form and redissolved or suspendedimmediately prior to use. Lyophilized forms are also included.

For oral administration, the pharmaceutical compositions may tale theform of, for example, tablets, lozanges, or capsules prepared byconventional means with pharmaceutically acceptable excipients such asbinding agents (e.g., pregelatinised maize starch, polyvinylpyrrolidoneor hydroxypropyl methylcellulose); fillers (e.g., lactose,microcrystalline cellulose or calcium hydrogen phosphate); lubricants(e.g., magnesium stearate, talc or silica); disintegrants (e.g., potatostarch or sodium starch glycolate); or wetting agents (e.g., sodiumlauryl sulphate). The tablets may be coated by methods well known in theart. Liquid preparations for oral administration may take the form of,for example, solutions, syrups or suspensions, or they may be presentedas a dry product for constitution with water or other suitable vehiclebefore use. Such liquid preparations may be prepared by conventionalmeans with pharmaceutically acceptable additives such as suspendingagents (e.g., sorbitol syrup, cellulose derivatives or hydrogenatededible fats); emulsifying agents (e.g., lecithin or acacia); non-aqueousvehicles (e.g., ationd oil, oily esters, ethyl alcohol or fractionatedvegetable oils); and preservatives (e.g., methyl orpropyl-p-hydroxybenzoates or sorbic acid). The preparations may alsocontain buffer salts, flavoring, coloring and sweetening agents asappropriate. Preparations for oral administration may be suitablyformulated to give controlled release of the active compound.

For administration by inhalation, the compounds may be convenientlydelivered in the form of an aerosol spray presentation from pressurizedpacks or a nebulizer, with the use of a suitable propellant, e.g.,dichlorodifluoromethane, trichlorofluoromethane,dichlorotetrafluoroethane, carbon dioxide or other suitable gas. In thecase of a pressurized aerosol the dosage unit may be determined byproviding a valve to deliver a metered amount. Capsules and cartridgesof e.g., gelatin, for use in an inhaler or insufflator may be formulatedcontaining a powder mix of the compound and a suitable powder base suchas lactose or starch.

The compounds may be formulated for parenteral administration byinjection, e.g., by bolus injection or continuous infusion. Formulationsfor injection may be presented in unit dosage form, e.g., in ampoules orin multi-dose containers, with an added preservative. The compositionsmay take such forms as suspensions, solutions or emulsions in oily oraqueous vehicles, and may contain formulatory agents such as suspending,stabilizing and/or dispersing agents. Alternatively, the activeingredient may be in powder form for constitution with a suitablevehicle, e.g., sterile pyrogen-free water, before use.

The compounds may also be formulated in rectal compositions such assuppositories or retention enemas, e.g., containing conventionalsuppository bases such as cocoa butter or other glycerides.

In addition to the formulations described previously, the compounds mayalso be formulated as a depot preparation. Such long acting formulationsmay be administered by implantation (for example subcutaneously orintramuscularly) or by intramuscular injection. Thus, for example, thecompounds may be formulated with suitable polymeric or hydrophobicmaterials (for example as an emulsion in an acceptable oil) or ionexchange resins, or as sparingly soluble derivatives, for example, as asparingly soluble salt.

Pharmaceutical compositions (including cosmetic preparations) maycomprise from about 0.00001 to 100% such as from 0.001 to 10% or from0.1% to 5% by weight of one or more compounds described herein.

In one embodiment, a compound described herein, is incorporated into atopical formulation containing a topical carrier that is generallysuited to topical drug administration and comprising any such materialknown in the art. The topical carrier may be selected so as to providethe composition in the desired form, e.g., as an ointment, lotion,cream, microemulsion, gel, oil, solution, or the like, and may becomprised of a material of either naturally occurring or syntheticorigin. It is preferable that the selected carrier not adversely affectthe active agent or other components of the topical formulation.Examples of suitable topical carriers for use herein include water,alcohols and other nontoxic organic solvents, glycerin, mineral oil,silicone, petroleum jelly, lanolin, fatty acids, vegetable oils,parabens, waxes, and the like.

Formulations may be colorless, odorless ointments, lotions, creams,microemulsions and gels.

Compounds may be incorporated into ointments, which generally aresemisolid preparations which are typically based on petrolatum or otherpetroleum derivatives. The specific ointment base to be used, as will beappreciated by those skilled in the art, is one that will provide foroptimum drug delivery, and, preferably, will provide for other desiredcharacteristics as well, e.g., emolliency or the like. As with othercarriers or vehicles, an ointment base should be inert, stable,nonirritating and nonsensitizing. As explained in Remington's, cited inthe preceding section, ointment bases may be grouped in four classes:oleaginous bases; emulsifiable bases; emulsion bases; and water-solublebases. Oleaginous ointment bases include, for example, vegetable oils,fats obtained from animals, and semisolid hydrocarbons obtained frompetroleum. Emulsifiable ointment bases, also known as absorbent ointmentbases, contain little or no water and include, for example,hydroxystearin sulfate, anhydrous lanolin and hydrophilic petrolatum.Emulsion ointment bases are either water-in-oil (W/O) emulsions oroil-in-water (O/W) emulsions, and include, for example, cetyl alcohol,glyceryl monostearate, lanolin and stearic acid. Exemplary water-solubleointment bases are prepared from polyethylene glycols (PEGs) of varyingmolecular weight; again, reference may be had to Remington's, supra, forfurther information.

Compounds may be incorporated into lotions, which generally arepreparations to be applied to the skin surface without friction, and aretypically liquid or semiliquid preparations in which solid particles,including the active agent, are present in a water or alcohol base.Lotions are usually suspensions of solids, and may comprise a liquidoily emulsion of the oil-in-water type. Lotions are preferredformulations for treating large body areas, because of the ease ofapplying a more fluid composition. It is generally necessary that theinsoluble matter in a lotion be finely divided. Lotions will typicallycontain suspending agents to produce better dispersions as well ascompounds useful for localizing and holding the active agent in contactwith the skin, e.g., methylcellulose, sodium carboxymethylcellulose, orthe like. An exemplary lotion formulation for use in conjunction withthe present method contains propylene glycol mixed with a hydrophilicpetrolatum such as that which may be obtained under the trademarkAquaphor® from Beiersdorf, Inc. (Norwalk, Conn.).

Compounds may be incorporated into creams, which generally are viscousliquid or semisolid emulsions, either oil-in-water or water-in-oil.Cream bases are water-washable, and contain an oil phase, an emulsifierand an aqueous phase. The oil phase is generally comprised of petrolatumand a fatty alcohol such as cetyl or stearyl alcohol; the aqueous phaseusually, although not necessarily, exceeds the oil phase in volume, andgenerally contains a humectant. The emulsifier in a cream formulation,as explained in Remington's, supra, is generally a nonionic, anionic,cationic or amphoteric surfactant.

Compounds may be incorporated into microemulsions, which generally arethermodynamically stable, isotropically clear dispersions of twoimmiscible liquids, such as oil and water, stabilized by an interfacialfilm of surfactant molecules (Encyclopedia of Pharmaceutical Technology(New York: Marcel Dekker, 1992), volume 9). For the preparation ofmicroemulsions, surfactant (emulsifier), co-surfactant (co-emulsifier),an oil phase and a water phase are necessary. Suitable surfactantsinclude any surfactants that are useful in the preparation of emulsions,e.g., emulsifiers that are typically used in the preparation of creams.The co-surfactant (or “co-emulsifer”) is generally selected from thegroup of polyglycerol derivatives, glycerol derivatives and fattyalcohols. Preferred emulsifier/co-emulsifier combinations are generallyalthough not necessarily selected from the group consisting of: glycerylmonostearate and polyoxyethylene stearate; polyethylene glycol andethylene glycol palmitostearate; and caprilic and capric triglyceridesand oleoyl macrogolglycerides. The water phase includes not only waterbut also, typically, buffers, glucose, propylene glycol, polyethyleneglycols, preferably lower molecular weight polyethylene glycols (e.g.,PEG 300 and PEG 400), and/or glycerol, and the like, while the oil phasewill generally comprise, for example, fatty acid esters, modifiedvegetable oils, silicone oils, mixtures of mono- di- and triglycerides,mono- and di-esters of PEG (e.g., oleoyl macrogol glycerides), etc.

Compounds may be incorporated into gel formulations, which generally aresemisolid systems consisting of either suspensions made up of smallinorganic particles (two-phase systems) or large organic moleculesdistributed substantially uniformly throughout a carrier liquid (singlephase gels). Single phase gels can be made, for example, by combiningthe active agent, a carrier liquid and a suitable gelling agent such astragacanth (at 2 to 5%), sodium alginate (at 2-10%), gelatin (at 2-15%),methylcellulose (at 3-5%), sodium carboxymethylcellulose (at 2-5%),carbomer (at 0.3-5%) or polyvinyl alcohol (at 10-20%) together andmixing until a characteristic semisolid product is produced. Othersuitable gelling agents include methylhydroxycellulose,polyoxyethylene-polyoxypropylene, hydroxyethylcellulose and gelatin.Although gels commonly employ aqueous carrier liquid, alcohols and oilscan be used as the carrier liquid as well.

Various additives, known to those skilled in the art, may be included informulations, e.g., topical formulations. Examples of additives include,but are not limited to, solubilizers, skin permeation enhancers,opacifiers, preservatives (e.g., anti-oxidants), gelling agents,buffering agents, surfactants (particularly nonionic and amphotericsurfactants), emulsifiers, emollients, thickening agents, stabilizers,humectants, colorants, fragrance, and the like. Inclusion ofsolubilizers and/or skin permeation enhancers is particularly preferred,along with emulsifiers, emollients and preservatives. An optimum topicalformulation comprises approximately: 2 wt. % to 60 wt. %, preferably 2wt. % to 50 wt. %, solubilizer and/or skin permeation enhancer; 2 wt. %to 50 wt. %, preferably 2 wt. % to 20 wt. %, emulsifiers; 2 wt. % to 20wt. % emollient; and 0.01 to 0.2 wt. % preservative, with the activeagent and carrier (e.g., water) making of the remainder of theformulation.

A skin permeation enhancer serves to facilitate passage of therapeuticlevels of active agent to pass through a reasonably sized area ofunbroken skin. Suitable enhancers are well known in the art and include,for example: lower alkanols such as methanol ethanol and 2-propanol;alkyl methyl sulfoxides such as dimethylsulfoxide (DMSO),decylmethylsulfoxide (C₁₀ MSO) and tetradecylmethyl sulfoxide;pyrrolidones such as 2-pyrrolidone, N-methyl-2-pyrrolidone andN-(-hydroxyethyl)pyrrolidone; urea; N,N-diethyl-m-toluamide; C₂-C₆alkanediols; miscellaneous solvents such as dimethyl formamide (DMF),N,N-dimethylacetamide (DMA) and tetrahydrofurfuryl alcohol; and the1-substituted azacycloheptan-2-ones, particularly1-n-dodecylcyclazacycloheptan-2-one (laurocapram; available under thetrademark Azone® from Whitby Research Incorporated, Richmond, Va.).

Examples of solubilizers include, but are not limited to, the following:hydrophilic ethers such as diethylene glycol monoethyl ether(ethoxydiglycol, available commercially as Transcutol®) and diethyleneglycol monoethyl ether oleate (available commercially as Softcutol®);polyethylene castor oil derivatives such as polyoxy 35 castor oil,polyoxy 40 hydrogenated castor oil, etc.; polyethylene glycol,particularly lower molecular weight polyethylene glycols such as PEG 300and PEG 400, and polyethylene glycol derivatives such as PEG-8caprylic/capric glycerides (available commercially as Labrasol™); alkylmethyl sulfoxides such as DMSO; pyrrolidones such as 2-pyrrolidone andN-methyl-2-pyrrolidone; and DMA. Many solubilizers can also act asabsorption enhancers. A single solubilizer may be incorporated into theformulation, or a mixture of solubilizers may be incorporated therein.

Suitable emulsifiers and co-emulsifiers include, without limitation,those emulsifiers and co-emulsifiers described with respect tomicroemulsion formulations. Emollients include, for example, propyleneglycol, glycerol, isopropyl myristate, polypropylene glycol-2 (PPG-2)myristyl ether propionate, and the like.

Other active agents may also be included in formulations, e.g., otheranti-inflammatory agents, analgesics, antimicrobial agents, antifungalagents, antibiotics, vitamins, antioxidants, and sunblock agentscommonly found in sunscreen formulations including, but not limited to,anthranilates, benzophenones (particularly benzophenone-3), camphorderivatives, cinnamates (e.g., octyl methoxycinnamate), dibenzoylmethanes (e.g., butyl methoxydibenzoyl methane), p-aminobenzoic acid(PABA) and derivatives thereof, and salicylates (e.g., octylsalicylate).

In certain topical formulations, the active agent is present in anamount in the range of approximately 0.25 wt. % to 75 wt. % of theformulation, preferably in the range of approximately 0.25 wt. % to 30wt. % of the formulation, more preferably in the range of approximately0.5 wt. % to 15 wt. % of the formulation, and most preferably in therange of approximately 1.0 wt. % to 10 wt. % of the formulation.

Topical skin treatment compositions can be packaged in a suitablecontainer to suit its viscosity and intended use by the consumer. Forexample, a lotion or cream can be packaged in a bottle or a roll-ballapplicator, or a propellant-driven aerosol device or a container fittedwith a pump suitable for finger operation. When the composition is acream, it can simply be stored in a non-deformable bottle or squeezecontainer, such as a tube or a lidded jar. The composition may also beincluded in capsules such as those described in U.S. Pat. No. 5,063,507.Accordingly, also provided are closed containers containing acosmetically acceptable composition as herein defined.

In an alternative embodiment, a pharmaceutical formulation is providedfor oral or parenteral administration, in which case the formulation maycomprises an activating compound-containing microemulsion as describedabove, but may contain alternative pharmaceutically acceptable carriers,vehicles, additives, etc. particularly suited to oral or parenteral drugadministration. Alternatively, an activating compound-containingmicroemulsion may be administered orally or parenterally substantiallyas described above, without modification.

Cells, e.g., treated ex vivo with a compound described herein, can beadministered according to methods for administering a graft to asubject, which may be accompanied, e.g., by administration of animmunosuppressant drug, e.g., cyclosporin A. For general principles inmedicinal formulation, the reader is referred to Cell Therapy: Stem CellTransplantation, Gene Therapy, and Cellular Immunotherapy, by G. Morstyn& W. Sheridan eds, Cambridge University Press, 1996; and HematopoicticStem Cell Therapy, E. D. Ball, J. Lister & P. Law, ChurchillLivingstone, 2000.

Also provided herein are kits, e.g., kits for therapeutic and/ordiagnostic purposes. A kit may include one or more compounds describedherein, and optionally devices for contacting tissue or cells with thecompounds. Devices include needles, syringes, stents, resuspensionliquid, and other devices for introducing a compound into a subject.

In any of the forgoing embodiments 1,5-bis(p-aminophenoxy)pentane may bespecifically excluded.

In any of the forgoing embodiments 11-cis-retinol may be specificallyexcluded.

In any of the forgoing embodiments 11-cis-retional palmitate may bespecifically excluded.

In any of the forgoing embodiments 13-cis-retinoic acid (accutane) maybe specifically excluded.

In any of the forgoing embodiments 2-bromopalmitic acid may bespecifically excluded.

In any of the forgoing embodiments 3-aminobenzoic acid ethyl estermethane sulfonate may be specifically excluded.

In any of the forgoing embodiments acetaminophen may be specificallyexcluded.

In any of the forgoing embodiments adamantylamine may be specificallyexcluded.

In any of the forgoing embodiments all-trans-retinaldehyde may bespecifically excluded.

In any of the forgoing embodiments all-trans-retinoic acid may bespecifically excluded.

In any of the forgoing embodiments all-trans-retinol (vitamin A) may bespecifically excluded.

In any of the forgoing embodiments all-trans-retinyl plamitate may bespecifically excluded.

In any of the forgoing embodiments analine may be specifically excluded.

In any of the forgoing embodiments cyclohexylamine may be specificallyexcluded.

In any of the forgoing embodiments dapson may be specifically excluded.

In any of the forgoing embodiments diaminophenoxypentane may bespecifically excluded.

In any of the forgoing embodiments ethyl m-aminobenzoate may bespecifically excluded.

In any of the forgoing embodiments m-aminobenzoic acid may bespecifically excluded.

In any of the forgoing embodiments m-phenetidine may be specificallyexcluded.

In any of the forgoing embodiments N-(4-hydroxyphenyl)retinamide(fenretinide) may be specifically excluded.

In any of the forgoing embodiments N,N-dimethylaniline may bespecifically excluded.

In any of the forgoing embodiments N,N-dimethyl-p-phenetidine may bespecifically excluded.

In any of the forgoing embodiments N-methylaniline may be specificallyexcluded.

In any of the forgoing embodiments N-methyl-p-phenetidine may bespecifically excluded.

In any of the forgoing embodiments o-phenetidine may be specificallyexcluded.

In any of the forgoing embodiments p-(n-hexyloxy)aniline may bespecifically excluded.

In any of the forgoing embodiments p-(n-hexyloxy)benzamide may bespecifically excluded.

In any of the forgoing embodiments p-(n-hexyloxy)benzoic acid hydrazidemay be specifically excluded.

In any of the forgoing embodiments p-anisidine may be specificallyexcluded.

In any of the forgoing embodiments p-ethylanaline may be specificallyexcluded.

In any of the forgoing embodiments p-ethyoxybenzylamine may bespecifically excluded.

In any of the forgoing embodiments p-ethyoxyphenol may be specificallyexcluded.

In any of the forgoing embodiments phenetidine may be specificallyexcluded.

In any of the forgoing embodiments piperidine may be specificallyexcluded.

In any of the forgoing embodiments p-n-boutoxyaniline may bespecifically excluded.

In any of the forgoing embodiments p-n-butylaniline may be specificallyexcluded.

In any of the forgoing embodiments p-n-dodecylaniline may bespecifically excluded.

In any of the forgoing embodiments p-nitroaniline may be specificallyexcluded.

In any of the forgoing embodiments sulfabenzamide may be specificallyexcluded.

In any of the forgoing embodiments sulfamoxaole may be specificallyexcluded.

In any of the forgoing embodiments sulfanilamide may be specificallyexcluded.

In any of the forgoing embodiments tricaine may be specificallyexcluded.

In addition, any compound cited in the references incorporated hereinmay also be specifically excluded from any of the forgoing embodiments.

4. Methods

Disclosed herein are methods for treating or preventing an ophtalmologicdisorder. An exemplary method comprises administering to a subject, e.g.a subject in need thereof, a therapeutically effective amount of acomposition, e.g., a pharmaceutical composition, described herein. Asubject in need thereof may be a subject who knows that he has or islikely to develop an opthalmologic disorder.

As discussed above, a disclosed composition may be administered to asubject in order to treat or prevent macular degeneration. Otherdiseases, disorders, or conditions characterized by the accumulation ofretinotoxic compounds, e.g., lipofuscin, in the RPE may be similarlytreated (e.g., lipofuscin-based retinopathies).

The methods described herein may be used for the treatment or preventionof any form of retinal or macular degeneration associated withlipofuscin accumulation, such as hereditary or degenerative diseases ofthe macula as e.g. age-related macular degeneration (AMD). There are twoforms of age-related macular degeneration, dry (atrophic) and wet(neovascular or exudative) macular degeneration.

As discussed above, macular degeneration (also referred to as retinaldegeneration) is a disease of the eye that involves deterioration of themacula, the central portion of the retina. Approximately 85% to 90% ofthe cases of macular degeneration are the “dry” (atrophic ornon-neovascular) type.

In “dry” macular degeneration, the deterioration of the retina isassociated with the formation of small yellow deposits, known as drusen,under the macula. This phenomena leads to a thinning and drying out ofthe macula. The location and amount of thinning in the retinal caused bythe drusen directly correlates to the amount of central vision loss.Degeneration of the pigmented layer of the retina and photoreceptorsoverlying drusen become atrophic and cause a slow of central vision.This often occurs over a decade or more. Vision loss can occur veryrapidly in subjects having strong geographic atrophy. Such subjects maybe treated as described herein.

Most people who lose vision from age related macular degeneration have“wet” macular degeneration. In “wet” (neovascular) macular degeneration,abnormal blood vessels from the choroidal layer of the eye, known assubretinal neovascularization grow under the retina and macula. Theseblood vessels tend to proliferate with fibrous tissue, and bleed andleak fluid under the macula, causing the macula to bulge or move anddistort the central vision. Acute vision loss occurs as transudate orhemorrhage accumulates in and beneath the retina. Permanent vision lossoccurs as the outer retina becomes atrophic or replaced by fibroustissues.

Stargardt's disease (STGD) is a recessive form of macular degenerationwith an onset during childhood. STGD is characterized clinically byprogressive loss of central vision and progressive atrophy of theretinal pigment epithelium (RPE) overlying the macula. Mutations in thehuman ABCR gene for RmP are responsible for STGD. Early in the diseasecourse, patients show delayed dark adaptation but otherwise normal rodfunction. Histologically, STGD is associated with deposition oflipofuscin pigment granules in RPE cells, presumably arising fromimpaired digestion after phagocytosis of shed distal outer-segments.Degeneration of the RPE occurs subsequently, with photoreceptordegeneration appearing late in the disease. This pathological picturehas lead to the conclusion that STGD is primarily a defect of the RPE.However, the pattern of early RPE degeneration and preservation ofphotoreceptors must be reconciled with the observation that RmP ispresent exclusively in outer segments and not expressed in RPE cells.Some AMDs are caused by mutations in a gene, such as the genes ABCA4,ELOVL4, PROML1, VMD2, Peripherin/RDS, EFEMP1, TIMP3, and XLRS1. Onemutation of the ABC4A gene is G1961E. Macular dystrophies also includethe following diseases: Stargardt disease/fundus flavimaculatus (OMIM248200), which is an autosomal recessive disease characterized by amutation at chromosome locus 1p21-p22 (STGD1); Stargardt-like maculardystrophy (OMIM 600110), which is an autosomal dominant diseasecharacterized by a mutation at chromosome locus 6q14 (STGD3);Stargardt-like macular dystrophy (OMIM 603786), which is an autosomaldominant disease characterized by a mutation at chromosome locus 4p(STGD4); autosomal dominant “bull's eye” macular dystrophy, which is anautosomal dominant disease characterized by a mutation at chromosomelocus 4p (MCDR2); Bestmacular dystrophy (OMIM 153700), which is anautosomal dominant disease characterized by a mutation at chromosomelocus 11q13; adult vitelliform dystrophy (OMIM 179605), which is anautosomal dominant disease characterized by a mutation at chromosomelocus 6p21.2-cen; pattern dystrophy (OMIM 169150), which is an autosomaldominant disease characterized by a mutation at chromosome locus6p21.2-cen; Doyne honeycomb retinal dystrophy (OMIM 126600), which is anautosomal dominant disease characterized by a mutation at chromosomelocus 2p16; North Carolina macular dystrophy (OMIM 136550), which is anautosomal dominant disease characterized by a mutation at chromosomelocus 6q14-q16.2 (MCDR1); autosomal dominant macular dystrophyresembling MCDR1, which is an autosomal dominant disease characterizedby a mutation at chromosome locus 5p15.33-p13.1 (MCDR3); NorthCarolina-like macular dystrophy associated with deafness, which is anautosomal dominant disease characterized by a mutation at chromosomelocus 14p (MCDR4); progressive biforcal chorioretinal atrophy (OMIM600790), which is an autosomal dominant disease characterized by amutation at chromosome locus 6q14-q16.2; Sorby's fundus dystrophy (OMIM136900), which is an autosomal dominant disease characterized by amutation at chromosome locus 22q12.1-q13.2; central areolar choroidaldystrophy (OMIM 215500), which is an autosomal dominant diseasecharacterized by a mutation at chromosome locus 6p21.2-cen17p13;dominant cystoid macular dystrophy (OMIM 153880), which is an autosomaldominant disease characterized by a mutation at chromosome locus7p15-p21; and juvenile retinoschisis (OMIM 312700), which is an X-linkeddisease characterized by a mutation at chromosome locus Xp22.2(Michaelides et al. (2003) J. Med. Genet. 40:641). The methods describedherein may be used to treat or prevent any of these geneticallyinhereted macular dystrophies, provided that they are associated withabnormal lipofuscin accumulation similar to AMD and Stargardt disease.

Other diseases that may be treated or prevented include cone-roddystrophy, certain types of retinitis pigmentosa, and fundusflavimaculatus.

In one embodiment, a drug is administered to a subject thatshort-circuits the visual cycle at a step of the visual cycle thatoccurs outside a disc of a rod photoreceptor cell. For example, as shownin FIG. 3, the drug may react with 11-cis-retinal in the RPE and shuntit to all-trans-retinal while it remains in the RPE. More specifically,the therapeutic may react with 11-cis-retinal to form an intermediatethat isomerizes to the all-trans configuration. The all-transintermediate may then release the therapeutic to form all-trans-retinal.The all-trans-retinal could then be re-processed through the remainderof the visual cycle as normal in the RPE. Thus, the visual cycle wouldbe reduced to a futile cycle, in which all-trans-retinal has little orno opportunity to accumulate in the disc.

In one embodiment, a subject may be diagnosed as having maculardegeneration, and then a disclosed drug or combination therapy may beadministered. In another embodiment, a subject may be identified asbeing at risk for developing macular degeneration (risk factors includea history of smoking, age, female gender, and family history). In yetanother embodiment, a subject may be diagnosed as having Stargardt'sdisease, a familial form of macular degeneration. In some embodiments, adrug may be administered prophylactically. In some embodiments, asubject may be diagnosed as having the disease before retinal damage isapparent. For example, a subject may be found to carry a gene mutationfor abcr, elovl4, and/or another gene, and thus be diagnosed as havingStargardt's disease before any opthalmologic signs are manifest, or asubject may be found to have early macular changes indicative of maculardegeneration before the subject is aware of any effect on vision. Insome embodiments, a human subject may know that he or she is in need ofthe macular generation treatment or prevention.

Doctors can usually diagnose macular degeneration by examining the eyeswith an opthalmoscope or a slit lamp. Sometimes fluoresceinangiography—a procedure in which a doctor injects dye into a vein andphotographs the retina—is used to determine the diagnosis. Lipofuscinaccumulation may be detected by autofluorescence imaging optionally withconfocal scanning laser opthalmoscope.

In some embodiments, a subject may be monitored for the extent ofmacular degeneration. A subject may be monitored in a variety of ways,such as by eye examination, dilated eye examination, fundoscopicexamination, visual acuity test, angiography, fluorescein angiography,and/or biopsy. Monitoring can be performed at a variety of times. Forexample, a subject may be monitored after a drug is administered. Themonitoring can occur one day, one week, two weeks, one month, twomonths, six months, one year, two years, and/or five years after thefirst administration of a drug. A subject can be repeatedly monitored.In some embodiments, the dose of a drug may be altered in response tomonitoring.

In some embodiments, the disclosed methods may be combined with othermethods for treating or preventing macular degeneration, such asphotodynamic therapy. Other methods are further described herein.

In some embodiments, a drug for treating or preventing maculardegeneration may be administered chronically. The drug may beadministered daily, more than once daily, twice a week, three times aweek, weekly, biweekly, monthly, bimonthly, semiannually, annually,and/or biannually.

The therapeutics may be administered by a wide variety routes, describedabove. In some embodiments, a drug may be administered orally, in theform of a tablet, a capsule, a liquid, a paste, and/or a powder. In someembodiments, a drug may be administered locally, as by intraocularinjection. In some embodiments, a drug may be administered systemicallyin a caged, masked, or otherwise inactive form and activated in the eye(such as by photodynamic therapy). In some embodiments, a drug may beadministered in a depo form, so sustained release of the drug isprovided over a period of time, such as hours, days, weeks, and/ormonths.

The therapeutic agents are used in amounts that are therapeuticallyeffective, which varies widely depending largely on the particular agentbeing used. The amount of agent incorporated into the composition alsodepends upon the desired release profile, the concentration of the agentrequired for a biological effect, and the length of time that thebiologically active substance has to be released for treatment. Incertain embodiments, the biologically active substance may be blendedwith a compound matrix at different loading levels, in one embodiment atroom temperature and without the need for an organic solvent. In otherembodiments, the compositions may be formulated as microspheres. In someembodiments, the drug may be formulated for sustained release.

It is noted that disruption of the visual cycle to prevent accumulationof A₂E may impair a subject's night (low-light) vision and might causenight-blindness. Indeed, some of the therapeutics noted herein asappropriate for preventing A₂E accumulation have been used sparingly inhumans or withheld from use entirely because of their propensity tocause night-blindness. However, with the recognition that this verycause of night blindness might be turned to the therapeutic and/orpreventative treatment of macular degeneration, it is likely thatpatients in need of such treatment would readily accept somenight-blindness in return for sparing of normal vision. This is becausethe visual cycle described above operates in rod photoreceptors, whichoperate only at low levels of illumination and do not operate during theday. Therefore, macular function would be little affected by decreasesin visual cycle function, while there might be some effect on low lightvision at night. At least some patients, and probably most, mightreadily sacrifice a decrement in night vision for a lessening of theprobability that they would eventually lose their cone day vision.

5. Screening Methods

Suitable drugs may be identified by a variety of screening methods. Forexample, a candidate drug may be administered to a subject that has oris at risk for having macular degeneration, e.g., an animal that is ananimal model for macular degeneration, and the accumulation of aretinotoxic compound, such as A₂E, can be measured. A drug that resultsin reduced accumulation of a retinotoxic compound compared to a control(absence of the drug) would thus be identified as a suitable drug.Alternatively, photoreceptor disks may be analyzed for the presence ofall-trans-retinal, N-retinylidene-PE, and/or A₂E. Animal models thathave rapid development of macular degeneration are of considerableinterest because naturally-occurring macular degeneration typicallytakes years to develop. A number of animal models are accepted modelsfor macular degeneration. For example, the abcr −/− knockout mouse hasbeen described as a model for macular degeneration and/or lipofuscinaccumulation, as has been the elovl4−/− knockout mouse. In addition,knockout mice deficient in monocyte chemoattractant protein-1 (Ccl-2;also known as MCP-1) or it cognate receptor, C—C chemokine receptor-2(Ccr-2), have also been described as accelerated models for maculardegeneration.

In addition, in vitro models of the visual system may facilitatescreening studies for drugs that inhibit or short circuit the visualcycle. In vitro models can be created by placing selected intermediatesin solution with appropriate enzymes and other necessary cofactors.Alternatively, an in vitro RPE culture system may be employed. Forexample, LRAT inhibition can be tested by adding a candidate drug to asolution containing LRAT and a substrate for LRAT, and measuringaccumulation of an expected product. Analogous systems are envisionedfor the other potential inhibition targets described herein.

Agents, such as small molecules, that inhibits one of the enzymes of thevisual cycle or shortcircuits the visual cycle may also be identified.For example, agents that bind to one of these enzymes may be identified.Screening assays may comprise contacting an enzyme with a test agent anddetermining whether the agent binds to the enzyme. An enzyme ofbiologically active fragment thereof may be used. The enzyme or fragmentmay be labeled, such as with a fluorophore. Screening assays may alsocomprise contacting an enzyme with its substrate in the presence of atest agent and determine whether the test agent prevents binding of theenzyme to the substrate. These assays may be adapted to highthroughputscreening assays.

Agents, such as small molecules, that inhibit vitamin A delivery to theeye may be identified in screening methods. A method may comprisecontacting an RBP with a test agent in the presence of vitamin A andmeasuring the amount of vitamin A bound to RBP in the presence relativeto the absence of the test agent. Another method may comprise contactingan RBP with a test agent in an vitro eye model, adding vitamin A, anddetermining the amount of vitamin A that is imported into the eye modelin the presence relative to the absence of the test agent. Otherscreening assays may comprise contacting an RBP and an RBP receptoroptionally in the presence of vitamin A and determining the amount ofRBP bound to the RBP receptor in the presence relative to the absence ofthe test agent.

EXAMPLES

The present description is further illustrated by the followingexamples, which should not be construed as limiting in any way. Thecontents of all cited references (including literature references,issued patents, published patent applications as cited throughout thisapplication) are hereby expressly incorporated by reference.

Example 1 TDT and TDH Bind to mRPE65 with High Affinities

Materials: Frozen bovine eye-cups devoid of retinas were purchased fromW. L. Lawson Co., Lincoln, Nebr. Ethylenediaminetetraacetic acid (EDTA),phenyl-Sepharose CL-4B, and Trizma® base, trans-trans-farnesol,pyridinium chlorochromate, Dess-Martin reagent, decyl magnesium bromide,hexadecyl amine, dimethylsulfoxide were from Sigma-Aldrich.Dithiothreitol (DTT) was from ICN Biomedicals Inc. Anagrade™ CHAPS wasfrom Anatrace. HPLC grade solvents were from Sigma-Aldrich Chemicals.Anti RPE65 (NFITKVNPETLETIK) antibody was obtained from Genmed Inc.Broad spectrum EDTA-free protease inhibitor cocktail was obtained fromRoche Biosciences. The precast gels (4-20%) for SDS-PAGE, BenchMarkprestained molecular weight marker were from Invitrogen. DEAE Sepharosewas from Amersham Biosciences. All reagents were analytical grade unlessspecified otherwise.

Methods

Animal Studies: Protocols were approved by the Standing Committee onAnimal Care of Harvard Medical School, the Institutional Animal Care andUse Committee of Columbia University and complied with guidelines setforth by The Association for Research in Vision and Opthalmology. 7 weekold male Balb/c albino mice and 7 week old male Sprague-Dawley rats werefrom Charles River Breeding Laboratories and were housed in 12:12 hlight:dark cycle. 8-10 week old Abcr null mutant mice (129/SV XC57BL/6J) were generated as formerly described (12,20) and Abcr^(−/−)and Abcr^(+/+) mice were raised under 12-hour on-off cyclic lightingwith an in-cage illuminance of 30-50 lux. In Abcr^(−/−) and Abcr^(+/+)mice, Rpe65 was 9 sequenced as reported previously [20].

Purification of mRPE65: mRPE65 was extracted and purified from thebovine eye cups using a procedure described earlier [29]. Protein puritywas established by silver staining and Western blotting (1:4000 primaryantibody-1 h at room temperature and 1:4000 secondary antibody 0.5 h atroom temperature). Buffers were changed by dialysis in the requestbuffer overnight in a Slide-a-lyser™ cassette from Pierce (10 KDa MWCO).RPE65 solutions were concentrated with an Amicon Ultra™ centrifugalfiltration device (30 KDa-cutoff) from Millipore Corp. The final proteinsolution contained 100 mM phosphate buffered saline (150 mM NaCl) pH 7.4and 1% CHAPSO. The protein concentration was measured by a modifiedLowry method [30] using the Bio-Rad DC protein assay protocol.

Syntheses:

13,17,21-Trimethyl-docosa-12,16,20-trien-11-one (TDT: A solution oftrans, trans-farnesal (200 mg, 0.9 mmol) in ether (2 mL) was added to asolution of decyl magnesium bromide (1 M solution in ether, 1.5 mL) at0° C. and stirred for 15 min. The reaction mixture was then warmed toroom temperature and quenched with aqueous saturated NH₄Cl (1 mL). H₂O(2 mL) was added and the reaction mixture was extracted with hexane (3×5mL). The combined extracts were collected, washed with brine, dried withmagnesium sulfate and evaporated under reduced pressure. The residue waschromatographed (SiO₂, EtOAc-light petroleum, 10:90) to give the alcohol(319 mg, 92%); R_(f) (EtOAc-light petroleum, 2:8) 0.56. Dess-Martinperiodinate (419 mg, 0.99 mmol) was added to a solution of the abovealcohol (319 mg, 0.83 mmol) in CH₂Cl₂ (1.5 mL) at room temperature andstirred for 10 min. The reaction mixture was then treated with sodiumthiosulfate-sodium bicarbonate solution (1:1 v/v of 10% sodiumthiosulfate and aqueous saturated NaHCO₃, 3 mL) and stirring continuedfor another 10 min. H₂O (2 mL) was added, the reaction mixture wasextracted with hexane (3×5 mL), washed with brine, dried with Mg₂SO4 andthe combined extracts were evaporated under reduced pressure. Theresidue was chromatographed (SiO₂, EtOAc-light petroleum, 1:99) to givethe ketone (TDT) (283 mg, 89%); R_(f)(EtOAc-light petroleum, 2:8) 0.8;δ_(H) (200 MHz; CDCl₃) 6.04 (s, 1H), 5.19-5.01 (m, 2H), 2.44-2.30 (m,2H), 2.20-1.85 (m, 8H), 1.71 (s, 3H), 1.59 (s, 6H), 1.55 (s, 3H) and1.38-1.17 (m, 21H); m/z (ESI) (Found: M+Na 383.3277, C₂₅H₄₄O requiresM+Na 383.3284).

3,7,11-Trimethyl-dodeca-2,6,10-trienoic acid hexadecylamide (TDH): NaCN(31 mg) and MnO₂ (590 mg) were added to a stirring solution oftrans-trans-farnesol (100 mg, 0.45 mmol) in hexane (3 mL) at roomtemperature, followed by hexadecyl amine (545 mg, 2.2 mmol) and stirringcontinued for 1 h. An additional portion of MnO₂ (590 mg) was added andthe mixture left for overnight at room temperature with stirring. Themixture was then filtered through a pad of silica and celite and washedwith hexane several times. The combined extracts were evaporated and theresidue was chromatographed (SiO₂, EtOAc-light petroleum, 3:97) to give3,7,11-Trimethyl-dodeca-2,6,10-trienoic acid hexadecylamide (145 mg,70%); R_(f)(EtOAc-light petroleum, 2:8) 0.52; δ_(H) (200 MHz; CDCl₃)8.18 (d, J=9 Hz, 1H), 6.0 (d, J=9.6 Hz, 1H), 5.2-5.0 (m, 2H), 3.42 (t,J=6.8 Hz, 2H), 2.23-1.91 (m, 8H), 1.67 (s, 3H), 1.59 (s, 9H), 1.39-1.20(m, 31H); m/z (ESI) (Found: M+Na 482.4334, C₃₁H₅₇ON requires M+Na482.2332).

Fluorescence binding assays: RPE65 in PBS, 1% CHAPS, pH 7.4 was used inthe fluorometric titration studies. All titrations were performed at 25°C. The samples in PBS buffer were excited at 280 nm and the fluorescencewas scanned from 300 to 500 nm. Fluorescence measurements, using 450 μLquartz cuvettes with a 0.5 cm path length, were made at 25° C. on aJobin Yvon Instruments, Fluoromax 2 employing the right-angle detectionmethod.

The fluorescence of the protein solution was measured afterequilibrating it at 25° C. for 10 min. The sample was then titrated witha solution of retinoid dissolved in DMSO in the absence of any overheadlight and the solution was mixed thoroughly before fluorescencemeasurement. In each titration, to a 350 μL solution of the protein anequivalent amount of ligand, typically 0.3 μL. was added and thoroughlymixed before allowing it to equilibrate for 10 min prior to recordingthe fluorescence intensity. The addition of DMSO (0.1% per addition) didnot have any effect on the fluorescence intensity. The binding constant(K_(D)) was calculated from the fluorescence intensity as describedbefore (17,19).

Drug treatment and retinoid extraction: The drugs were injected i.p inDMSO as carrier. Controls received DMSO alone. The volume of thesolution was 50 μL for mice and 180 μL for rats. After the injectionswere given the animals were housed in dark for 2 h and then bleached for2 h. Then the animals were dark adapted (5 min for mice and 30 min forrats) before being sacrificed and eyes were enucleated. In theexperiments performed male Balb/c mice and male Sprague Dawley rats wereused.

Eyes were placed in glass-glass homogenizer in 0.8 mL of 1 Mhydroxylamine/0.1 M MOPS [3-(N-morpholino) propanesulfonic acid], pH 6.5and 0.2% SDS and homogenized [31]. Ethanol (0.6 mL) was added and thehomogenates were incubated for 30 min at room temperature to allowformation of the 11-cis-retinal oximes [31]. The retinoids wereextracted with dichloromethane (3×0.4 mL). The combined extracts weredried with magnesium sulfate, evaporated under the flow of argon andsubjected to HPLC analysis. The normal phase HPLC column was YMC-PVA SILNP, 250×4.6 mm and the mobile phase was hexane-dioxane (93:7 v/v) with aflow rate of 1.5 mL/min. Absorbance was monitored at 325 nm, and peakswere identified by comparing with standards. In the HPLC profiles shown,retinyl esters and 11-cis-retinal syn-oxime were measured. Regenerationtime was 5 min with mice and 30 min with rats. The rates of regenerationand the effects of the drugs appeared indistinguishable between theBalbc/mice and the pigmented wt (129/SV X C57BL/6J) mice (on the samegenetic background as the Abcr knockout mice).

Electroretinogram Determinations (ERG): Mice were dark-adapted overnightbefore all ERG experiments. To determine the acute effect of compoundsunder study, mice were given a single i.p. injection of a compound at 50mg/kg in 25 uL DMSO under dim red light and kept in darkness for anadditional 1 h before being exposed to the bleaching light prior to ERGrecordings. Control (“untreated”) animals were injected with 25 uL ofDMSO. Mice were anaesthetized with ketamine (80 mg/kg) and xylazine(5-10 mg/kg) and pupils were dilated with 1% phenylephrine and 1%cyclopentolate, followed by an exposure to 5000 lux bleaching light for2 min. The ERG was recorded from the cornea with a cotton wick salineelectrodes for about 50 min immediately after bleaching. Subcutaneous 30gauge needles on the forehead and trunk were used as reference andground electrodes, respectively. The animals rested on a heatermaintaining the body temperature at 37° C. The light stimulus wasobtained from a ganzfeld stimulator having a stroboscope (PS33 GrassInstruments Inc., West Warwick, R.I.) removed from its housing andrecessed above and behind the head of the mouse. The flash was diffusedto cover the ganzfeld homogeneously. Maximum flash intensity wasmeasured with a calibrated light meter (J16 Tektronics Instruments,Beaverton, Oreg.). Responses were averaged by a Macintoshcomputer-controlled data acquisition system (PowerLab, AD Instruments,Mountain View, Calif.) at a frequency of 0.1 Hz.

The same animals were subjected to ERG experiments according to exactlythe same protocol 3 days later, except no (repeated) injection ofcompounds was performed.

Tissue extraction and HPLC analysis: Posterior eye cups were pooled andhomogenized in PBS using a tissue grinder. An equal volume of a mixtureof chloroform/methanol (2:1) was added and the sample was extractedthree times. To remove insoluble material, extracts were filteredthrough cotton and passed through a reversed phase (C18 Sep-Pak,Millipore) cartridge with 0.1% TFA in methanol. After removing solventby evaporation under gas, the extract was dissolved in methanolcontaining 0.1% TFA, for HPLC analysis. For quantification of A₂E, aWaters Alliance 2695 HPLC was employed with a Atlantis® dC18 column(Waters, 4.6×150 mm, 3 μm) and the following gradient of acetonitrile inwater (containing 0.1% trifluoroacetic acid): 90-100% (0-10 min), 100%acetonitrile (10-20 min), and a flow rate of 0.8 mL/min with monitoringat 430 nm. The injection volume was 10 μL. Extraction and injection forHPLC were performed under dim red light. Levels of A₂E and iso-A₂E weredetermined by reference to an external standard of HPLC-purifiedA₂E/iso-A₂E. Since A₂E and iso-A₂E reach photoequilibrium in vivo [4],use of the term A₂E will refer to both isomers, unless stated otherwise.

Results

Design and In Vitro Activities of Specific mRPE65 Antagonists: Inprevious quantitative fluorescence studies we showed that mRPE65saturably binds all-trans-retinyl palmitate (tRP) with a K_(D)=47 nM[17,19]. Further structure-activity studies on ligand binding to mRPE65reveals that amide and ketone equivalents of tRP bound approximately aswell as tRP itself [unpublished data]. Moreover, isoprenoids, such asC15 farnesyl, can substitute for the all-trans-retinyl moiety[unpublished data]. Based on these observations we prepared the trans,trans-farnesylated ketone (TDT) and amide (TDH) shown in FIGS. 4A-B. TDTand TDH specifically bind to purified bovine mRPE65 as shown byfluorescence titration of mRPE65 with TDT and TDH reported in FIGS.4A-B. The excitation wavelength was at 280 nm and the emission wasobserved through 0.5 cm layer of solution. The titration solutionconsisted of 0.952 μM of mRPE65 in 100 mM phosphate buffered saline (150mM NaCl) pH 7.4 and 1% CHAPS. Panel (a) of FIG. 4A shows the emissionspectra of mRPE65 when binding to TDT. Panel (b) shows the change in thefluorescence intensity at 338 nm with increasing concentrations of TDTor TDH. Panel (c) shows the linear square fit plots of the equation P₀αvs R₀α/(1−α), for the titration of mRPE65 vs. TDT or TDH [17,19]. TDTbinds with K_(D)=58±5 nM while TDH binds with K_(D)=96±14 nM. In theseexperiments, we made use of the fact that the specific binding of theseanalogs to mRPE65 quenches protein fluorescence.

In Vivo Studies with Analogs TDT and TDH

Acute effects: In order to determine whether TDT and TDH have an effecton the visual cycle in vivo, the overnight dark-adapted Abca4^(+/+)(Rpe65 450Leu, pigmented, 129/SV X C57BL/6J) mice received single (i.p.)injections of the two compounds at 50 mg/kg. For comparison, mice werealso injected with 13-cis-retinoic acid (13-RA; Accutane) at the sameconcentration. One hour after treatment, the mice were subjected tophoto-bleaching (5000 lux for 2 min to bleach ˜90% of rhodopsin) andERGs were recorded.

FIG. 5A shows the effects of TDT and TDH on the ERG b-wave amplitudes inanimals 1 h after treatment with 50 mg/kg dose of three compounds(13-RA, TDT and TDH) on rod b-wave amplitude recovery afterphoto-bleaching. Results are averaged from three mice in each group withSD bars shown. Both isoprenoids delayed the recovery of dark-adaptedvisual responses to an extent similar to that of 13-RA as judged fromdark-adapted ERG b-wave amplitudes recorded using dim light flashesdelivered immediately before and at regular intervals afterphoto-bleaching. A substantial effect on rod b-wave recovery induced byTDT and TDH was still present 3 days after treatment while no sustainedeffect of 13-RA was detected (FIG. 5B).

To establish whether recovery of the dark-adapted rod b-wave wasretarded because of an effect on 11-cis-retinal synthesis we studied theeffects of TDT on 11-cis-retinal regeneration in rats and mice. The11-cis-retinal that is regenerated is essentially all bound to rhodopsinin rodents, so that measuring its level is equivalent to measuring therhodopsin content [27]. Initial experiments were performed on SpragueDawley rats because similar experiments using 13-RA were previouslycarried out using these animals so that ready comparisons of potency andeffectiveness can be made [24]. In these experiments, 13-RA was shown toexhibit profound effects on visual cycle function by interfering with11-cis-retinal regeneration after a bleaching [24]. Accordingly, in thecurrent experiments, the rats were given single injections (i.p.) of TDT(TDH) (50 mg/kg in DMSO), 13-RA (50 mg/kg in DMSO), and DMSO alone.After injecting the analogs, the rats were dark adapted for 2 h, andthen exposed to light that led to <10% of dark adapted 11-cis-retinal inthese animals, compared to dark adapted controls (data not shown). Afterallowing the bleached rats to dark-adapt again for 30 min, the animalswere sacrificed, and the regenerated 11-cis-retinal was determined asindicated in Methods. In these experiments, the amount of resynthesized11-cis-retinal, the chromophore of rhodopsin, is measured by HPLC andcompared to the amounts of all-trans-retinyl ester precursor.

As shown in FIGS. 6A-C, both 13-RA (FIG. 6A) and TDT (FIG. 6B) achievedsubstantial (4-5-fold) inhibition of 11-cis-retinal regeneration, whilethe inhibitory effect of TDH (FIG. 6C) is less pronounced than with TDT.These figures show results of HPLC analysis of extracted retinoids fromdrug treated rats. FIG. 6A shows HPLC data from 13-RA treated SpragueDawley rats. In FIG. 6A, the relative amounts of11-cis-retinal-syn-oxime and all-trans-(cis)-retinyl esters are shownfor the control (—13-RA) (top) and drug treated animals (bottom). InFIG. 6B, the corresponding data are shown for the TDT treated rats(top-control, bottom TDT treated). In this case, the ester pool in thedrug treated rat is largely, if not exclusively, all-trans. FIG. 6Cshows corresponding data for TDH treated rats (top-control, bottom TDHtreated). These results are consistent with the observed lower potencyof TDH as an mRPE65 antagonist compared to TDT. Upon repetition of theexperiments two further times the average inhibition values are asfollows: 13-RA (78±2%), TDT (79±4%), and TDH (55±2%). These percentinhibition values are generated by comparing the integrated areas underthe retinyl ester and 11-cis-retinal-syn-oxime peaks. (Materials andMethods).

It is significant that the all-trans-retinyl ester pool increases at theexpense of the 11-cis-retinal pool in the presence of TDT and TDH (FIGS.6A-C). The concomitant increase in the all-trans-retinyl ester pool isexpected of an antagonist of mRPE65. The magnitude of inhibition by13-RA is approximately the same as reported [25]. In the case of 13-RAinhibition, the ester pool is a mixture of the 11-cis and all-transisomers because of the inhibition of 11-cis-retinol-dehydrogenase[22,25]. In the experiments described here with the isoprenoidantagonists, only all-trans-retinyl esters are detectable [data notshown].

Similar experiments with inhibitors were also performed in Balb/c mice.Here again inhibition is observed, but the effects are less pronouncedthan in rats, both with 13-RA and the isoprenoid antagonists. Theinhibition values are as follows: 13-RA (33±4%), TDT (35±2%), and TDH(24±6%). It is noteworthy that in rats the 11-cis chromophore isregenerated considerably more slowly than in mice [27]. In mice, as inrats, the isoprenoid mRPE65 antagonists and 13-RA proved to beapproximately equi-potent with respect to the inhibition of11-cis-retinal regeneration.

b) Effect of the long-term (chronic) treatment of ABAC4^(−/−) mice withTDT and TDH on A₂E accumulation: The RPE65 antagonists TDT and TDH werefurther tested for their abilities to reduce the accumulation of the RPElipofuscin fluorophores A₂E and iso-A₂E. Beginning at 2 months of age,Abca4^(−/−) mice (on the same genetic background as the Abca4^(+/+)animals) were given i.p. injections of the two compounds at 50 mg/kgtwice a week and A₂E and iso-A₂E levels were determined by quantitativeHPLC after an additional 2 months.

As shown in FIGS. 7A-D, both compounds, but especially TDT, were highlyefficient in lowering A₂E accumulation. FIGS. 7A-D show quantitation ofA₂E and iso-A₂E in eye cups of Abcr −/− mice. (A-C) Typicalchromatograms obtained by reverse-phase HPLC with monitoring at 430 nmillustrate the detection of A₂E and iso-A₂E and a reduction in peakintensity with TDT and TDH treatment relative to vehicle-treatedcontrols. FIG. 7D: A₂E/iso-A₂E quantitation from integrated peak areasnormalized to external standards. Values expressed as picomoles per eyeand are based on single samples obtained by pooling 4 eyes.

Specifically, the levels of A₂E in eyecups of mice treated with TDT were85% lower than in vehicle-treated (DMSO) Abca4^(−/−) animals. This is anunder estimate of the extent of A₂E reduction because drug treatment didnot commence until two months of age, and the data is not corrected forA₂E accumulation in the knockout mice up to this point. These resultsdemonstrate that the mRPE65 antagonists TDT and TDH are effective invivo and slow the rate of A₂E accumulation by limiting visual cyclefunction.

Discussion

RPE65 is of central importance in the operation of the visual cycle andbeen shown to be necessary for rhodopsin regeneration [15]. The retinoicacids specifically bind to mRPE65 and can block isomerization in RPEmembranes [22]. The fact that 13-RA limits the visual cycle in rats invivo [24] suggests the possibility that mRPE65 might be a viable targetfor interfering with toxic lipofuscin formation. In rats, the effects of13-RA on visual function are pronounced. There is an approximately4-fold inhibition measured for 11-cis-retinal regeneration afterbleaching [24]. This inhibition is translated into a diminution in theaccumulation of the lipofuscins in the A₂E series in the Abca4^(−/−)knockout mouse model [25]. However, since the retinoic acids exhibitpleotropic effects, we undertook to prepare non-retinoid antagonists ofmRPE65 to directly determine if inhibition of this target in and ofitself could limit the visual cycle, establish that RPE65 function ispart of the rate-limiting step in visual pigment regeneration, andlessen the accumulation of the retinotoxic lipofuscins.

Two non-retinoid antagonists of mRPE65 were readily designed and shownto bind potently to mRPE65, a target unique to the visual cycle. BothTDT and TDH inhibited 11-cis-retinal regeneration after photobleachingto approximately the same extent as 13-RA. However unlike 13-RA, bothTDT and TDH are directed solely at mRPE65, and in vivo inhibitionresults are consistent with this protein being the operant target.Rodents treated with TDT and TDH accumulate all-trans-retinyl estersbehind the mRPE65 block. This result is expected, because theall-trans-retinyl esters are converted into 11-cis-retinol more slowlywhen mRPE65 is inhibited. By comparison, in the presence of 13-RA, theaccumulation of both all-trans-retinyl and 11-cis-retinyl esters isnoted [24]. This occurs because 13-RA inhibits both mRPE65 and11-cis-retinol dehydrogenase [22,23].

Chronic treatment with TDT and TDH had profound effects on limiting A₂Eaccumulation in the animal model of STGD, the Abca4^(−/−) mice. TDT, inparticular, prevented A₂E formation by approximately 85% compared tountreated Abca4^(−/−) animals, and brought A₂E levels down toapproximately those observed in wt animals of similar age. Therelationship between the extent of inhibition of visual cycle turnoverand A₂E accumulation remains to be explored. It is likely to benon-linear, at least in part due to the fact that A₂E formation issecond order in all-trans-retinal. Other non-linear effects may operateas well.

With respect to the pharmacology of the isoprenoid mRPE65 antagonists,it should be noted that the effects of both TDT and TDH aresubstantially more persistent than with 13-RA, probably because they aremore hydrophobic than the retinoic acids. An increase in hydrophobicitytends to slow down rates of elimination of drugs. In addition, animalstreated with TDT and TDH tolerated the compounds extremely well, showingno obvious signs of toxicity and/or distress, even when the compoundswere administered every 48 h.

In conclusion, we have designed and studied specific, non-retinoidmRPE65 antagonists, which inhibit 11-cis-retinal regeneration afterbleaching, further supporting the hypothesis that mRPE65 is minimallypart of the rate-limiting process in visual pigment regeneration. Theanalogs described here will be useful in a chemical genetic approach tothe temporal function of mRPE65 in visual cycle function visual pigmentregeneration. Similar analogs will be used to probe the function of thecongeneric sRPE65 as it relates to the regulation of the visual cycle[19]. In addition to analyzing the function of RPE65 in vitro, thenon-retinoid antagonists also profoundly inhibited lipofuscin A₂Eaccumulation in the Abca4^(−/−) mouse model of macular degeneration. Ourstudies suggest that these, or similar molecules, may be efficient andnon-toxic candidates as drugs aimed at preventing the onset oflipofuscin-sensitive forms of macular degeneration, including STGD and aprevalent form of AMD (geographic atrophy) leading to visual loss [28].

References cited in Example 1.

-   -   1). Lamb, T. D et al. (2004) Prog. Retin. Eye Res. 23: 307-380;        2). Salcmar, T. P. et al. (2002) Ann. Rev. Biophys. and        Biomolec. Struct. 31: 443-484; 3). Rattner, A. et al. (2000) J.        Biol. Chem. 275: 11034-11043; 4). Parish, C. A. et al. (1998)        Proc. of the Natl. Acad. of Sci. (U.S.A.) 95: 14609-14613; 5).        Sparrow, J. R. et al. (2000) Invest. Opthalmol. Vis. Sci. 41:        1981-1989; 6). Mata, N. L. et al. (2000) Proc. Natl. Acad. Sci.        U.S.A., 97: 7154-7159; 7). Fishkin, N. E. et al. (2005) Proc.        Natl. Acad. Sci. U.S.A., 10: 7091-7096; 8). Allikmets, R. et        al. (1997) Nat Genet 15: 236-246; 9). Allikmets, R. et al.        (1997b) Science 277: 1805-1807; 10). Allikmets, R. (2000a) Am J        Hum Genet 67: 793-799; 11). Beharry, S. et al. (2004) J Biol        Chem 279: 53972-53979; 12). Weng, J. et al. (1999) Cell 98:        13-23; 13). Bavik, C. O. et al. (1991) J. Biol. Chem. 266:        14978-14985; 14). Hamel, C. P. et al. (1993) J. Neurosci. Sci.        34: 414-425; 15). Redmond, T. M. et al. (1998) Nat. Genet. 20:        344-351; 16). Jahng, W. J. et al. (2003) Biochemistry 42:        6159-6168; 17). Gollapalli, D. R. et al. (2003) Biochemistry 42:        11824-11830, erratum in: Biochemistry 43: 7226 (2003); 18).        Mata, N. L. et al. (2004) J. Biol. Chem. 279: 635-643; 19).        Xue, L. et al. (2004) Cell 117: 761-771; 20). Kim, S. R. et        al. (2004) Proc. Natl. Acad. Sci. USA 101: 11668-11672; 21).        Lyubarsky, A. L. et al. (2005) Biochemistry 44: 9880-9888; 22).        Gollapalli, D. R et al. (2004) Proc. Natl. Acad. Sci. U.S.A.        101, 10030-10035; 23). Law, W. C. et al. (1989) Biochem.        Biophys. Res. Commun. 161: 825-829; 24). Sieving, P. A. et        al. (2001) Proc. Natl. Acad. Sci. USA 98:1835-1840; 25).        Radu, R. A. et al. (2003) Proc. Natl Acad Sci USA 100:        4742-4747; 26). Guzzo, C. A. et al. (1996) in Goodman and        Gilman's: The Pharmacological Basis of Therapeutics, 9th Ed,        eds. Hardman, J. G. & Limbird, L. E. (McGraw Hill, New York),        pp. 1598-1602; 27). Van Hooser, J. P. et al. (2000) Methods in        Enzymology, 316: 565-575; 28). Holz, F. G. et al. (2001) Invest.        Opthalmol. Vis. Sci. 42, 1051-1056; 29). Ma, J. et al. (2001)        Invest. Opthalmol. Vis. Sci. 42: 1429-1435; 30). Lowry, O. H. et        al. (1951) J. Biol. Chem., 193: 265-275; and 31).        Groenendijk, G. W. T. et al. (1980) Biochim. Biophys. Acta. 617:        430-438.

The examples should not be construed as limiting in any way. Thecontents of all cited references (including literature references,issued patents, published patent applications as cited throughout thisapplication) are hereby expressly incorporated by reference.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents of the specificembodiments described herein.

1. A compound of formula XI:

wherein, independently for each occurrence, n is 0 to 10 inclusive; R¹is hydrogen or alkyl; R² is hydrogen, alkyl, cycloalkyl, alkenyl,cycloalkenyl, alkynyl, aryl, or aralkyl; Z is cycloalkyl, alkenyl,cycloalkenyl, alkynyl, aryl, aralkyl, —C(═O)R_(b), or —(CH₂)_(p)R_(b); pis 0 to 20 inclusive; R_(a) is hydrogen, alkyl, cycloalkyl, alkenyl,cycloalkenyl, alkynyl, aryl, or aralkyl; R_(b) is hydrogen, alkyl,cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl, or aralkyl; and

denotes a single bond or a trans double bond; provided that the compoundis not N-(4-hydroxyphenyl)retinamide.
 2. The compound of claim 1,wherein R¹ is hydrogen or methyl.
 3. The compound of claim 1, wherein Zis aryl.
 4. The compound of claim 1, wherein R_(a) is hydrogen.
 5. Acompound of claim 1, wherein said compound of formula XI is a compoundof formula XIa:

wherein, independently for each occurrence, n is 0 to 10 inclusive; R¹is hydrogen or alkyl; R² is hydrogen, alkyl, cycloalkyl, alkenyl,cycloalkenyl, alkynyl, aryl, or aralkyl; R³, R⁴, R⁵, R⁶ and R⁷ arehydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl,aralkyenyl, aralkynyl, heteroaralkyl, heteroaralkyenyl, heteroaralkynyl,cyano, nitro, sulfhydryl, hydroxyl, sulfonyl, amino, acylamino, amido,alkylthio, carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate,sulfonamido, sulfamoyl, sulfonyl, or sulfoxido; R_(a) is hydrogen,alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl, or aralkyl; and

denotes a single bond or a trans double bond; provided that the compoundis not N-(4-hydroxyphenyl)retinamide.
 6. The compound of claim 5,wherein R¹ is hydrogen or methyl.
 7. The compound of claim 5, whereinR_(a) is hydrogen.
 8. The compound of claim 5, wherein R³, R⁴, R⁶ and R⁷are hydrogen.
 9. The compound of claim 5, wherein R⁵ is hydroxyl.
 10. Acompound of claim 1, wherein said compound of formula XI is a compoundof formula XIb:

wherein, independently for each occurrence, n is 0 to 5 inclusive; R¹ ishydrogen or methyl; R² is hydrogen, alkyl, alkenyl, alkynyl, aryl,

R³, R⁴, R⁵, R⁶, R⁷ and R⁸ are hydrogen, halogen, alkyl, alkenyl,alkynyl, aryl, heteroaryl, aralkyl, aralkyenyl, aralkynyl,heteroaralkyl, heteroaralkyenyl, heteroaralkynyl, cyano, nitro,sulfhydryl, hydroxyl, sulfonyl, amino, acylamino, amido, alkylthio,carboxyl, carbamoyl, alkoxyl, sulfonate, sulfate, sulfonamido,sulfamoyl, sulfonyl, or sulfoxido; any two geminal R⁸ and the carbon towhich they are bound may represent C(═O); and R_(a) is hydrogen, alkyl,cycloalkyl, alkenyl, cycloalkenyl, alkynyl, aryl, or aralkyl; providedthat the compound is not N-(4-hydroxyphenyl)retinamide.
 11. The compoundof claim 10, wherein R¹ is hydrogen or methyl.
 12. The compound of claim10, wherein R_(a) is hydrogen.
 13. The compound of claim 10, wherein R³,R⁴, R⁶ and R⁷ are hydrogen.
 14. The compound of claim 10, wherein R⁵ ishydroxyl.
 15. The compound of claim 10, wherein n is 1 to 3 inclusive.16. The compound of claim 10, wherein R² is


17. The compound of claim 10, wherein R² is


18. The compound of claim 10, wherein R² is


19. A compound of formula IV:

wherein, independently for each occurrence, n is 1, 2, 3 or 4; X is —O—,—NR_(a)—, —C(R_(b))₂- or —C(═O)—; Z is —C(═O)R_(b), —OR_(b), —N(R_(b))₂,alkyl or haloalkyl; R_(a) is hydrogen, alkyl, haloalkyl, aryl oraralkyl; and R_(b) is hydrogen, alkyl, haloalkyl, aryl or aralkyl.
 20. Acompound having a structure represented by


21. A formulation comprising a compound defined by claim 1, and a secondcompound, different from the first compound, wherein said secondcompound is selected from compounds of formula I, II, III, IV, V, VI,VII, VIII, IX, or X. 22-27. (canceled)
 28. A formulation comprising acompound defined by claim 19, and a second compound, different from thefirst compound, wherein said second compound is selected from compoundsof formula I, II, III, IV, V, VI, VII, VIII, IX, or X.
 29. A formulationcomprising a compound defined by claim 20, and a second compound,different from the first compound, wherein said second compound isselected from compounds of formula I, II, III, IV, V, VI, VII, VIII, IX,or X.
 30. A method for treating or preventing an opthalmologic disorderin a subject comprising administering to a subject a pharmaceuticallyacceptable amount of a compound of claim
 1. 31. A method for treating orpreventing an opthalmologic disorder in a subject comprisingadministering to a subject a pharmaceutically acceptable amount of acompound of claim
 19. 32. A method for treating or preventing anopthalmologic disorder in a subject comprising administering to asubject a pharmaceutically acceptable amount of a compound of claim 20.